Develop Reference

Form Validation: messages not displaying when all input fields are left empty

So I am practicing Javascript and right now I am trying to implement form validation.
One of the issues I am having is that when I click on the button when all of the input fields are empty, the first one (Full Name) only highlights and displays a message (Please checkout snippet). I was wondering is that how it works - can only one message be displayed at a time or is there a way to get all of the input fields to change color and display messages for each empty field?
function validateForm(e) {
const eName = document.getElementById("FullName");
const eMail = document.getElementById("Email");
const ePhone = document.getElementById("PhoneNumber");
const ePass = document.getElementById("Password");
const eCnfmPass = document.getElementById("ConfirmPassword");
const phoneno = /^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$/;
const fullNameText = "Oops, please fill out your name";
const emailText = "Please enter a valid email";
const phoneText = "Please enter a valid phone number";
const passText = "Please enter a valid password";
const confirmText = "Please confirm your password";
//Name input validation - If input is left empty
if (eName.value === "") {
e.preventDefault();
document.getElementById("FullName").style.borderColor = "red";
document.getElementById("FullNameLabel").innerHTML = fullNameText;
document.getElementById("FullNameLabel").style.color = "red";
return false;
}
//Email input validation - If input is left empty
if (eMail.value === "") {
e.preventDefault();
document.getElementById("Email").style.borderColor = "red";
document.getElementById("EmailLabel").innerHTML = emailText;
document.getElementById("EmailLabel").style.color = "red";
return false;
}
//Phone number input validation - If input is left empty
if (ePhone.value === "") {
e.preventDefault();
document.getElementById("PhoneNumber").style.borderColor = "red";
document.getElementById("PhoneNumberLabel").innerHTML = phoneText;
document.getElementById("PhoneNumberLabel").style.color = "red";
return false;
}
//Phone number input validation - checks to see if there is a missing number or character that is not a number
if (ePhone.value.match(phoneno)) {
return true;
} else {
alert("Please check your phone number and enter it again")
// document.getElementById("PhoneNumber").style.borderColor = "red";
// document.getElementById("PhoneNumberLabel").innerHTML = phoneText;
// document.getElementById("PhoneNumberLabel").style.color = "red";
return false;
}
//Password input validation - If input is left empty
if (ePass.value === "") {
e.preventDefault();
document.getElementById("Password").style.borderColor = "red";
document.getElementById("PasswordLabel").innerHTML = passText;
document.getElementById("PasswordLabel").style.color = "red";
return false;
}
//Confirm password input validation - If input is left empty
if (eCnfmPass.value === "") {
e.preventDefault();
document.getElementById("ConfirmPassword").style.borderColor = "red";
document.getElementById("ConfirmPswdLabel").innerHTML = confirmText;
document.getElementById("ConfirmPswdLabel").style.color = "red";
}
}
//Checks to make sure that both password and confirm passwords match
var passConfirm = function() {
if (document.getElementById("Password").value ==
document.getElementById("ConfirmPassword").value) {
document.getElementById("Message").style.color = "green";
document.getElementById("Message").style.fontWeight = "Heavy";
document.getElementById("Message").innerHTML = "Passwords match!"
} else {
document.getElementById("Message").style.color = "red";
document.getElementById("Message").style.fontWeight = "Heavy";
document.getElementById("Message").innerHTML = "Passwords do NOT match!"
}
}
<div class="container">
<form class="form" onsubmit="validateForm(event)">
<div>
<label id="FullNameLabel">Full Name</label></br>
<input type="text" placeholder="John Doe" id="FullName" />
</div>
<div>
<label id="EmailLabel">Email</label></br>
<input type="text" placeholder="johndoe#email.com" id="Email" />
</div>
<div>
<label id="PhoneNumberLabel">Phone Number</label></br>
<input type="text" placeholder="(123) 456-7890" id="PhoneNumber" />
</div>
<div>
<label id="PasswordLabel">Password</label></br>
<input name="Password" id="Password" type="Password" placeholder="Password" onkeyup='passConfirm();' />
</div>
<div>
<label id="ConfirmPswdLabel">Confirm Password</label></br>
<input name="ConfirmPassword" id="ConfirmPassword" type="Password" placeholder="Confirm Password" onkeyup='passConfirm();' />
</div>
<span id="Message"></span>
<button type="submit" value="submit">Sign Me Up!</button>
</form>
</div>

You have too much javascript code, you can simplify that, alot.
to check if any of the inputs are empty, you can first store all the inputs in a variable like that:
let inputs = document.querySelectorAll('.form input') //This will make a Nodelist array of all the inputs inside the form.
let labels = document.querySelectorAll('.form label') //This will make a Nodelist array of the label tags inside the form
after that you can loop through the inputs array to find if any of the inputs are empty:
for (let i = 0; i < inputs.length; i++) {
if (inputs.value.length == 0) {
inputs[i].style.borderColor = 'red'
label[i].textContent = 'Please fill in this input'
}
}

Require your inputs. Why go through all that trouble making sure they're filled out?
<input required>

Text obtained with innerHTML dissapear

I have the following code:
function passVerif() {
if (document.forms['form'].pass.value === "") {
messagePV.innerHTML = ("Password field is empty!")
//alert("Password field is empty!");
return false;
}
return true;
}
function emailVerif() {
if (document.forms['form'].email.value === "") {
messageEV.innerHTML = ("Email field is empty!")
//alert("Email field is empty!");
return false;
}
return true;
}
function validate() {
var email = document.getElementById("input").value;
var emailFilter = /^([a-zA-Z0-9_.-])+#(([a-zA-Z0-9-])+.)+([a-zA-Z0-9]{2,4})+$/;
if (!emailFilter.test(email)) {
messageV.innerHTML = ("Please enter a valid e-mail address!")
//alert('Please enter a valid e-mail address!');
return false;
}
}
<div>
<form name="form"> Login<br>
<input type="text" name="email" placeholder="Enter email here" id="input" class="input">Email address<br>
<input type="password" name="pass" placeholder="Enter password here" class="input">Password<br>
<input type="button" name="required" onclick="return passVerif(), emailVerif(), validate()">
</form>
</div>
<div id="messagePV"></div>
<div id="messageEV"></div>
<div id="messageV"></div>
As you can see, input type is submit. Because of that (page is refreshing after click on button) the text I want to show disappears after refresh.
As I read on other posts, the simple change from submit to button will do the dew.
But I am suspecting that I messed up the return false and return true instructions in all of my functions.
Is this correct? If they are in a logical way I can avoid the page refresh and continue to use submit? At least until all conditions are met and the form is good to go.
In other words, can someone help me to put return false and true in such way that the page will refresh only if all conditions are met.
Thanks a lot, I am not even a noob.
Codes are copied from different sources on the internet. I am at the very beginning of coding road. Please have mercy :)

I would change it to one validation function and have a bool that is returned based on if it has errored or not:
// Just have one validation function
function validate() {
var errorMessage = ''; // build up an error message
var email = document.forms['form'].email.value;
var emailFilter = /^([a-zA-Z0-9_.-])+#(([a-zA-Z0-9-])+.)+([a-zA-Z0-9]{2,4})+$/;
if (email === "") {
errorMessage += "Email field is empty!<br>";
} else if (!emailFilter.test(email)) { // this can be else if
errorMessage += "Please enter a valid e-mail address!<br>";
}
if (document.forms['form'].pass.value === "") {
errorMessage += "Password field is empty!<br>"
}
if (errorMessage === '') {
return true; // return true as no error message
} else {
document.getElementById('error-message').innerHTML = errorMessage; // show error message and return false
return false;
}
}
<div>
<form name="form"> Login<br>
<input type="text" name="email" placeholder="Enter email here" id="input" class="input">Email address<br>
<input type="password" name="pass" placeholder="Enter password here" class="input">Password<br>
<input type="submit" name="required" onclick="return validate();">
</form>
</div>
<div id="error-message">
<!-- CAN HAVE ONE ERROR MESSAGE DIV -->
</div>

I tried with your code and I could find the the messages were not getting updated based on the conditions. So I did few modifications to your code to display the message based on which condition fails.
HTML
<div>
<form name="form"> Login<br>
<input type="text" name="email" placeholder="Enter email here" id="input" class="input">Email address<br><br>
<input type="password" name="pass" placeholder="Enter password here" class="input">Password<br><br>
<input type="submit" name="required" value="Submit" onclick="return passVerif(), emailVerif(), validate()">
</form>
</div>
<div id="messagePV"></div>
<div id="messageEV"></div>
<div id="messageV"></div>
JS
function passVerif() {
messagePV.innerHTML = ("")
if(document.forms['form'].pass.value === "") {
messagePV.innerHTML = ("Password field is empty!")
//alert("Password field is empty!");
return false;
}
return true;
}
function emailVerif() {
messageEV.innerHTML = ("")
if(document.forms['form'].email.value === "") {
messageEV.innerHTML = ("Email field is empty!")
//alert("Email field is empty!");
return false;
}
return true;
}
function validate() {
messageV.innerHTML = ("")
var email = document.getElementById("input").value;
var emailFilter = /^([a-zA-Z0-9_.-])+#(([a-zA-Z0-9-])+.)+([a-zA-Z0-9]{2,4})+$/;
if (!emailFilter.test(email)) {
messageV.innerHTML = ("Please enter a valid e-mail address!")
//alert('Please enter a valid e-mail address!');
return false;
}
}
By initializing the errormessage filed to empty sting u can maintain the fresh set of error messages.
Jsfiddle: https://jsfiddle.net/85w7qaqx/1/
Hope this helps out.

Javascript Coding in HTML

For an assignment I have I am writing a registration form. My question is how would I connect the first statement, and the function below so when someone types in their email in the text box it checks to see if the email is valid? (document.getElementById('user').value)
<input id="user" type="text" onblur="isUserNameValid();"></input><br/>
function isEmailValid(email) {
"use strict";
var e = email.split("#"), local = /[^\w.!#$%&*+-\/=?^_{|}~]/, domain = /[\w.-]/;
if (e.length !== 2) {
return false;
}
if (local.test(e[0])) {
return false;
}
if (e[0].length > 253) {
return false;
}
if ((e[0][0] === ".") || (/\.\./.test(e[0]))) {
return false;
}
if (domain.test(e[1])) {
return false;
}
if (e[1].length > 253) {
return false;
}
if (e[1][0] === "." || /\.\./.test(e[1]) || e[1][e[1].length - 1] === ".") {
return false;
}
return true;
}

As you confirmed you can use HTML5, simply change your input to the below and the browser will validate the email for you when the form is submitted.
<input id="user" name="user" type="email" /><br/>
N.B. You can use a self closing tag for an input. You should also assign the name attribute of the input as that is what is used as the key for the data when it is submitted to the server.

<input type="text" id="email" name="email" onblur="javascript:return validate();"/>
<script>
function validate() {
var reg = /^([A-Za-z0-9_\-\.])+\#([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
var address = document.getElementById("email").value;
if (reg.test(address) == false) {
alert('Invalid Email Address');
return false;
} else {
alert('valid Email Address');
return false;
}
}
</script>

validation of input text field in html using javascript

<script type='text/javascript'>
function required()
{
var empt = document.forms["form1"]["Name"].value;
if (empt == "")
{
alert("Please input a Value");
return false;
}
}
</script>
<form name="form1" method="" action="">
<input type="text" name="name" value="Name"/><br />
<input type="text" name="address line1" value="Address Line 1"/><br />
I have more than one input text field, each having their default value. Before I submit the form I have to verify whether all fields are filled. So far i got the javascript to check for null since different text boxes have different default value. How can I write a javascript to verify that user has entered data? I mean, the script must identify that input data is other than default and null.

If you are not using jQuery then I would simply write a validation method that you can be fired when the form is submitted. The method can validate the text fields to make sure that they are not empty or the default value. The method will return a bool value and if it is false you can fire off your alert and assign classes to highlight the fields that did not pass validation.
HTML:
<form name="form1" method="" action="" onsubmit="return validateForm(this)">
<input type="text" name="name" value="Name"/><br />
<input type="text" name="addressLine01" value="Address Line 1"/><br />
<input type="submit"/>
</form>
JavaScript:
function validateForm(form) {
var nameField = form.name;
var addressLine01 = form.addressLine01;
if (isNotEmpty(nameField)) {
if(isNotEmpty(addressLine01)) {
return true;
{
{
return false;
}
function isNotEmpty(field) {
var fieldData = field.value;
if (fieldData.length == 0 || fieldData == "" || fieldData == fieldData) {
field.className = "FieldError"; //Classs to highlight error
alert("Please correct the errors in order to continue.");
return false;
} else {
field.className = "FieldOk"; //Resets field back to default
return true; //Submits form
}
}
The validateForm method assigns the elements you want to validate and then in this case calls the isNotEmpty method to validate if the field is empty or has not been changed from the default value. it continuously calls the inNotEmpty method until it returns a value of true or if the conditional fails for that field it will return false.
Give this a shot and let me know if it helps or if you have any questions. of course you can write additional custom methods to validate numbers only, email address, valid URL, etc.
If you use jQuery at all I would look into trying out the jQuery Validation plug-in. I have been using it for my last few projects and it is pretty nice. Check it out if you get a chance. http://docs.jquery.com/Plugins/Validation

<form name="myForm" id="myForm" method="post" onsubmit="return validateForm();">
First Name: <input type="text" id="name" /> <br />
<span id="nameErrMsg" class="error"></span> <br />
<!-- ... all your other stuff ... -->
</form>
<p>
1.word should be atleast 5 letter<br>
2.No space should be encountered<br>
3.No numbers and special characters allowed<br>
4.letters can be repeated upto 3(eg: aa is allowed aaa is not allowed)
</p>
<button id="validateTestButton" value="Validate now" onclick="validateForm();">Validate now</button>
validateForm = function () {
return checkName();
}
function checkName() {
var x = document.myForm;
var input = x.name.value;
var errMsgHolder = document.getElementById('nameErrMsg');
if (input.length < 5) {
errMsgHolder.innerHTML =
'Please enter a name with at least 5 letters';
return false;
} else if (!(/^\S{3,}$/.test(input))) {
errMsgHolder.innerHTML =
'Name cannot contain whitespace';
return false;
}else if(!(/^[a-zA-Z]+$/.test(input)))
{
errMsgHolder.innerHTML=
'Only alphabets allowed'
}
else if(!(/^(?:(\w)(?!\1\1))+$/.test(input)))
{
errMsgHolder.innerHTML=
'per 3 alphabets allowed'
}
else {
errMsgHolder.innerHTML = '';
return undefined;
}
}
.error {
color: #E00000;
}

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>Validation</title>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script type="text/javascript">
var tags = document.getElementsByTagName("input");
var radiotags = document.getElementsByName("gender");
var compareValidator = ['compare'];
var formtag = document.getElementsByTagName("form");
function validation(){
for(var i=0;i<tags.length;i++){
var tagid = tags[i].id;
var tagval = tags[i].value;
var tagtit = tags[i].title;
var tagclass = tags[i].className;
//Validation for Textbox Start
if(tags[i].type == "text"){
if(tagval == "" || tagval == null){
var lbl = $(tags[i]).prev().text();
lbl = lbl.replace(/ : /g,'')
//alert("Please Enter "+lbl);
$(".span"+tagid).remove();
$("#"+tagid).after("<span style='color:red;' class='span"+tagid+"'>Please Enter "+lbl+"</span>");
$("#"+tagid).focus();
//return false;
}
else if(tagval != "" || tagval != null){
$(".span"+tagid).remove();
}
//Validation for compare text in two text boxes Start
//put two tags with same class name and put class name in compareValidator.
for(var j=0;j<compareValidator.length;j++){
if((tagval != "") && (tagclass.indexOf(compareValidator[j]) != -1)){
if(($('.'+compareValidator[j]).first().val()) != ($('.'+compareValidator[j]).last().val())){
$("."+compareValidator[j]+":last").after("<span style='color:red;' class='span"+tagid+"'>Invalid Text</span>");
$("span").prev("span").remove();
$("."+compareValidator[j]+":last").focus();
//return false;
}
}
}
//Validation for compare text in two text boxes End
//Validation for Email Start
if((tagval != "") && (tagclass.indexOf('email') != -1)){
//enter class = email where you want to use email validator
var reg = /^\w+([-+.']\w+)*#\w+([-.]\w+)*\.\w+([-.]\w+)*$/
if (reg.test(tagval)){
$(".span"+tagid).remove();
return true;
}
else{
$(".span"+tagid).remove();
$("#"+tagid).after("<span style='color:red;' class='span"+tagid+"'>Email is Invalid</span>");
$("#"+tagid).focus();
return false;
}
}
//Validation for Email End
}
//Validation for Textbox End
//Validation for Radio Start
else if(tags[i].type == "radio"){
//enter class = gender where you want to use gender validator
if((radiotags[0].checked == false) && (radiotags[1].checked == false)){
$(".span"+tagid).remove();
//$("#"+tagid").after("<span style='color:red;' class='span"+tagid+"'>Please Select Your Gender </span>");
$(".gender:last").next().after("<span style='color:red;' class='span"+tagid+"'> Please Select Your Gender</span>");
$("#"+tagid).focus();
i += 1;
}
else{
$(".span"+tagid).remove();
}
}
//Validation for Radio End
else{
}
}
//return false;
}
function Validate(){
if(!validation()){
return false;
}
return true;
}
function onloadevents(){
tags[tags.length -1].onclick = function(){
//return Validate();
}
for(var j=0;j<formtag.length;j++){
formtag[j].onsubmit = function(){
return Validate();
}
}
for(var i=0;i<tags.length;i++){
var tagid = tags[i].id;
var tagval = tags[i].value;
var tagtit = tags[i].title;
var tagclass = tags[i].className;
if((tags[i].type == "text") && (tagclass.indexOf('numeric') != -1)){
//enter class = numeric where you want to use numeric validator
document.getElementById(tagid).onkeypress = function(){
numeric(event);
}
}
}
}
function numeric(event){
var KeyBoardCode = (event.which) ? event.which : event.keyCode;
if (KeyBoardCode > 31 && (KeyBoardCode < 48 || KeyBoardCode > 57)){
event.preventDefault();
$(".spannum").remove();
//$(".numeric").after("<span class='spannum'>Numeric Keys Please</span>");
//$(".numeric").focus();
return false;
}
$(".spannum").remove();
return true;
}
if (document.addEventListener) {
document.addEventListener("DOMContentLoaded", onloadevents, false);
}
//window.onload = onloadevents;
</script>
</head>
<body>
<form method="post">
<label for="fname">Test 1 : </label><input type="text" title="Test 1" id="fname" class="form1"><br>
<label for="fname1">Test 2 : </label><input type="text" title="Test 2" id="fname1" class="form1 compare"><br>
<label for="fname2">Test 3 : </label><input type="text" title="Test 3" id="fname2" class="form1 compare"><br>
<label for="gender">Gender : </label>
<input type="radio" title="Male" id="fname3" class="gender" name="gender" value="Male"><label for="gender">Male</label>
<input type="radio" title="Female" id="fname4" class="gender" name="gender" value="Female"><label for="gender">Female</label><br>
<label for="fname5">Mobile : </label><input type="text" title="Mobile" id="fname5" class="numeric"><br>
<label for="fname6">Email : </label><input type="text" title="Email" id="fname6" class="email"><br>
<input type="submit" id="sub" value="Submit">
</form>
</body>
</html>

function hasValue( val ) { // Return true if text input is valid/ not-empty
return val.replace(/\s+/, '').length; // boolean
}
For multiple elements you can pass inside your input elements loop their value into that function argument.
If a user inserted one or more spaces, thanks to the regex s+ the function will return false.

<pre><form name="myform" action="saveNew" method="post" enctype="multipart/form-data">
<input type="text" id="name" name="name" />
<input type="submit"/>
</form></pre>
<script language="JavaScript" type="text/javascript">
var frmvalidator = new Validator("myform");
frmvalidator.EnableFocusOnError(false);
frmvalidator.EnableMsgsTogether();
frmvalidator.addValidation("name","req","Plese Enter Name");
</script>
before using above code you have to add the gen_validatorv31.js js file

For flexibility and other places you might want to validated. You can use the following function.
`function validateOnlyTextField(element) {
var str = element.value;
if(!(/^[a-zA-Z, ]+$/.test(str))){
// console.log('String contain number characters');
str = str.substr(0, str.length -1);
element.value = str;
}
}`
Then on your html section use the following event.
<input type="text" id="names" onkeyup="validateOnlyTextField(this)" />
You can always reuse the function.

HTML Form Validation via Javascript

I want to keep viewers from entering words like "fssadf", and force them to enter a valid email which must contain the "#" in the middle and "." to prevent spam and injection.
I also want the form to display an error message that says "change the email field to the correct email"
I use js_function.js which contain this:
function validEmail()
{
var reg = /^([A-Za-z0-9_\-\.])+\#([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
var email_address = $("#email").val();
if(reg.test(email_address) == false)
return false;
else
return true;
}
but it does not prevent the viewer from sending me "sfdasfd" instead of a valid email.
What can I do to achieve the above?
check out the files below:
http://www.mediafire.com/?kx5bvttc0s2fbrs
thanks,
rami

Though I didn't see any error on my program what you provided but still you may
use
var reg = /^[_a-z0-9]+(\.[a-z0-9-]+)*#[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$/;
instead of this
var reg = /^([A-Za-z0-9_\-\.])+\#([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
I think that will help. I provided the total Javascript code what worked properly for me.
function validEmail()
{
var reg = /^[_a-z0-9]+(\.[a-z0-9-]+)*#[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$/;
var email_address = $("#email").val();
if(reg.test(email_address) == false)
return false;
else
return true;
}
Use this
or you may use this too in other way
HTML
<form>
//Other Codes
<input type="text" name="email" id="email" onchange="validate(this.value)" />
//Other Codes
</form>
And Javascript
<script>
function validate(email)
{
var reg = /^[_a-z0-9]+(\.[a-z0-9-]+)*#[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$/;
if(reg.test(email) == false)
{
alert("This is a invalid Email Address!");
document.getElementById('email').value = '';
document.getElementById('email').focus();
return false;
}
else{
return true;
}
}
</script>
OR
HTML
<form>
//Other Codes
<input type="text" name="email" id="email" onchange="validate()" />
//Other Codes
</form>
And Javascript
<script>
function validate()
{
var reg = /^[_a-z0-9]+(\.[a-z0-9-]+)*#[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$/;
var email = document.getElementById('email').value;
if(reg.test(email) == false)
{
alert("This is a invalid Email Address!");
document.getElementById('email').value = '';
document.getElementById('email').focus();
return false;
}
else{
return true;
}
}
</script>
And the last solution will be quiet easier to apply I think.
Error Message on Page instead of Popup
HTML
<form>
//Other Codes
<input type="text" name="email" id="email" onchange="validate()" />
<span id="errormessage"></span>
//Other Codes
</form>
And Javascript
<script>
function validate()
{
var reg = /^[_a-z0-9]+(\.[a-z0-9-]+)*#[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$/;
var email = document.getElementById('email').value;
if(reg.test(email) == false)
{
document.getElementById('errormessage').innerHTML= 'fill your email';
document.getElementById('email').value = '';
document.getElementById('email').focus();
return false;
}
else{
document.getElementById('errormessage').innerHTML= '';
return true;
}
}
</script>

try with this
$(document).ready(function() {
$('#btn-submit').click(function() {
$(".error").hide();
var hasError = false;
var emailReg = /^([\w-\.]+#([\w-]+\.)+[\w-]{2,4})?$/;
var emailaddressVal = $("#UserEmail").val();
if(emailaddressVal == '') {
$("#UserEmail").after('<span class="error">Please enter your email address.</span>');
hasError = true;
}
else if(!emailReg.test(emailaddressVal)) {
$("#UserEmail").after('<span class="error">Enter a valid email address.</span>');
hasError = true;
}
if(hasError == true) { return false; }
});
});

Duplicate of this question:
Validate email address in JavaScript?
There is some valuable discussion in the comments about edge cases that SHOULD NOT be ignored.
Did you try to Google this one before you asked? IT is a /very/ common question.

If you're after a pure HTML5 solution using jQuery.... Here's a live demo
HTML
<form id="form">
Email <input name="field1" required="required" type="email" /> <br />
<div id="error"></div>
<input required="required" name="submit" type="submit" />
</form>​
Code
$(document).ready(function() {
var validCheckInput = function() {
if ($(this)[0].checkValidity()) {
$(this).removeClass("error");
$("#error").empty();
} else {
$(this).addClass("error");
$("#error").text("change the email field to the correct email");
}
if ($("#form")[0].checkValidity()) {
$("#form input[type='submit']").removeAttr("disabled");
} else {
$("#form input[type='submit']").attr("disabled", "disabled");
}
};s
var binds = function(validCheck) {
$(this).change(validCheck);
$(this).focus(validCheck);
$(this).keyup(validCheck);
validCheck.call($(this));
}
$("#form input").each(function() {binds.call(this, validCheckInput)});
});​
CSS
.error {
border: 2px solid red;
}​