Javascript return false, alert not working - javascript

i'm trying to make sure certain fields are not left blank in my form. it seems simple enough but for some reason it's not working. The alert is not showing, and return false is not working (it continues to post blank entries into my database) please help, what am i doing wrong. thank you!
the script:
function check(){
var name = getElementById('name');
var date = getElementById('date');
var pri = getElementById('pri');
var asapc = getElementById('asapc');
var asapn = getElementById('asapn');
var obr = getElementById('obr');
var obc = getElementById('obc');
var obn = getElementById('obn');
if (name.value == "" || date.value == "" || pri.value == "not" || asapc.value == "" || asapn.value == "" || obr.value == "" || obc.value == "" || obn.value == "") {
alert( "One or more fields were not filled out." );
return false ; }
return true;
}
The code:
<FORM ACTION="step2.php" METHOD="POST" onsubmit="check();">
<!-- fields here -->
<INPUT TYPE="submit" VALUE="CONTINUE">

access every element as document.getElementById... and in form tag write this onsubmit="return check();" instead if onsubmit="check();"

You are missing return here:
<FORM ACTION="step2.php" METHOD="POST" onsubmit="return check();">

You are missing (document) this is the correct syntax:
document.getElementById('id');
<script>
function check() {
var name = document.getElementById('name');
var date = document.getElementById('date');
if (name.value == "" || date.value == "") {
alert( "One or more fields were not filled out.");
return false;
}
}
</script>
and getElementByID means by ID not my tagName
<FORM ACTION="step2.php" METHOD="POST" onsubmit="return check();">
<input name="name" type="text" value="" id="name">
<input name="date" type="text" value="" id="date">
.....etc..
<INPUT TYPE="submit" VALUE="CONTINUE">
</FORM>

Related

Why is my form still submitting even though it returns false?

I made this code which submits a form with a name and age field with a submit button. My code looks like this:
function checkForm() {
var name = document.forms["form"]["name"].value;
var age = document.forms["form"]["age"].value;
var regName = /^[A-Z]*[a-z]{3,} $/;
var regAge = /^[\d.*]{1,} $/;
if (name == regName && age == regAge) {
return true;
} else {
return false;
}
}
<form name="form" action="register.php" method="POST" onsubmit="return checkForm()">
<p>Name:</p>
<input type="text" name="name" id="name">
<br>
<p>Age:</p>
<input type="text" name="age" id="age">
<br>
<br>
<button type="submit" name="submit">Submit</button>
</form>
The name should be using only upper case and lower case letters and the age must be numerical and a positive integer.
Supposedly, when I entered the wrong data, the form should not return false but its returning true and sending me through to register.php. Is there something wrong with my code?
Try evaluating regex With pattern.test('stringMethod')
function checkForm(event){
var name = document.forms["form"]["name"].value;
var age = document.forms["form"]["age"].value;
var regName = /^[A-Z]*[a-z]{3,} $/;
var regAge = /^[\d.*]{1,} $/;
if (regName.test(name) && regAge.test(age)){
return true;
} else{
event.preventDefault();
return false;
}
}
Try to add event.preventDefault(); when the data is invalid.
function checkForm(event){
var name = document.forms["form"]["name"].value;
var age = document.forms["form"]["age"].value;
var regName = /^[A-Z]*[a-z]{3,} $/;
var regAge = /^[\d.*]{1,} $/;
if (name == regName && age == regAge){
return true;
} else{
event.preventDefault();
return false;
}
}
Form default behaviour is like that if you are calling a function on submit it will get submit. So you can call the function on button submit.
<button type="submit" name="submit" onsubmit="return checkForm()">Submit</button>

How to make Javascript alert code all on one line

I'm trying to figure out how to make the alert code "First and Last Name must be filled out" if both of the fields of the form have no information inserted. I know how to do them individually, but how do you do make an alert code for both messages combined on one line? I am pretty new to Javascript..
<!DOCTYPE html>
<html>
<head>
<script>
function validateForm() {
var x = document.forms["myForm"]["fname"].value;
var y = document.forms["myForm"]["lname"].value;
if (x == null || x == "") {
alert("First Name is missing information");
return false;
}
else (y == null || y == "") {
alert("Last Name is missing information")
return false;
}
else (x == null || x == "" && y == null || y == "") {
alert("First and Last name are missing information")
return false;
}
}
</script>
</head>
<body>
<form name="myForm" action="demo_form.asp"
onsubmit="return validateForm()" method="post">
First Name: <input type="text" name="fname"><br>
Last Name: <input type="text" name="lname"><br>
<input type="submit" value="Submit">
</form>
</body>
</html>
Delete all your JavaScript.
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<form action="demo_form.asp" method="post">
First Name: <input type="text" name="fname" required /><br />
Last Name: <input type="text" name="lname" required /><br />
<input type="submit" value="Submit" />
</form>
</body>
</html>
Notice the required attribute on the form.
Don't use JavaScript to do HTML's job.
Your logic needs to be reversed so that the case where both are null is checked first or the code will never get to it because either the x or y case happens first. Try:
var x = document.forms["myForm"]["fname"].value;
var y = document.forms["myForm"]["lname"].value;
var emptyX = x == null || x == "";
var emptyY = y == null || y == "";
if (emptyX && emptyY) {
alert("First and Last name are missing information")
return false;
}
else (emptyX) {
alert("First Name is missing information");
return false;
}
else (emptyY) {
alert("Last Name is missing information")
return false;
}
You should move your final else statement to the top. As your code currently exists, both fields will not be checked if either the first or last names are found to be empty.
Alternatively, you could add logic in each of x and y to check if the other is not empty but this isn't necessary if you just reverse the code.

form is submitting instead return false javascript

I am trying to test my form for validation. I don't have an .asp or .php file so I was informed I could use action="". My code doesn't seem to function right.On codepen it shows as values being posted. Jsfiddle gives me an error thats a paragraph long. In browser the page just seems to refresh. I have no alerts showing for anything....
what am I doing wrong here?
HTML:
<form name="name_form" action="" onsubmit="ValidateFormJS()" method="post">
First Name:
<input type="text" name="first_name">
<br> Last Name:
<input type="text" name="last_name">
<br>
<input type="submit" value="Submit">
</form>
Javascript:
function ValidateFormJS() {
var first = document.forms["name_form"]["first_name"].value;
var last = document.form["name_form"]["last_name"].value;
if (first == null || first == "") {
alert("First name must be filled out.");
return false;
} else if (last == null || last == "") {
alert("Last name must be filled out.");
return false;
} else {
alert("Form Submitted.");
return true;
}
}
The returned values from the function are never used.
You forgot return before the function call on onsubmit event.
onsubmit="return ValidateFormJS()"
Another problem is that you're using document.form to get the value of last name. It should be document.forms.
The last else can be removed.
Demo
var form = document.forms["name_form"];
function ValidateFormJS() {
var first = form["first_name"].value,
last = form["last_name"].value;
if (first == null || first == "") {
alert("First name must be filled out.");
return false;
} else if (last == null || last == "") {
alert("Last name must be filled out.");
return false;
}
}
<form name="name_form" action="" onsubmit="return ValidateFormJS()" method="post">
First Name:
<input type="text" name="first_name">
<br>Last Name:
<input type="text" name="last_name">
<br>
<input type="submit" value="Submit">
</form>
try this
in view
<form name="name_form" action="" onsubmit="return ValidateFormJS();" method="post">
in js code
function ValidateFormJS() {
var first = document.forms["name_form"]["first_name"].value;
var last = document.form["name_form"]["last_name"].value;
if (first == null || first == "") {
alert("First name must be filled out.");
return false;
} else if (last == null || last == "") {
alert("Last name must be filled out.");
return false;
}
alert("Form Submitted.");
return true;
}

Validation code issue

I'm trying to create a simple validation script which checks if text was entered or not in a textbox. I wrote the following code, which unfortunately does not print the alert.
<html>
<head>
<title> Js Page </title>
<script>
function validateName()
{
var FirstName=document.forms["myForm"]["firstname"].value;
if(FirstName==null || FirstName=="" )
{
alert("Please insert the corect First/Lastname");
return false;
}
}
</script>
</head>
<body>
<form name = "myForm" onsubmit = "return validateName()" method="post">
First name: <input type="text" name="firstname"><br>
<input type="submit" value="Submit">
</form>
</body>
</html>
It is better to use id
<input type="text" name="firstname" id="firstnameId">
function validateName()
{
if(document.getElementById("firstnameId").value == ""){
alert("Please insert the corect First/Lastname");
return false;
} else
return true;
}
From firefox error console:
Timestamp: 6/29/2013 5:37:41 PM Error: SyntaxError: missing } after
function body Source File:
file:///C:/Users/developer/Desktop/adad.html Line: 13
You're missing } in function body.
function validateName()
{
var FirstName=document.forms["myForm"]["firstname"].value;
if(FirstName==null || FirstName=="" )
{
alert("Please insert the corect First/Lastname");
return false;
}
}
you are miising "}" at the in your jaavascript function
try to add developer tools of your browser it is advisable to use.
Maybe it would ignore the emptiness because of the space characters. You should use trim().
var FirstName = document.forms["myForm"]["firstname"].value.trim();
if(FirstName == ""){
}
is good for checking emptiness.
you can also use jQuery:
(give id="firstname" in your textox)
$(document).ready(function() {
$('#login').click(function() {
var username = $('#firstname').val();
if ($.trim(username).length == 0) {
alert('Please enter User name.');
return false;
e.preventDefault();
}
});
});
this is the complete validation for email
<script>
function validateForm()
{
var x=document.forms["register"]["email"].value;
var atpos=x.indexOf("#");
var space=x.indexOf(" ");
var dollar=x.indexOf("$");
var hash=x.indexOf("#");
var per=x.indexOf("%");
var or=x.indexOf("^");
var amber=x.indexOf("&");
var star=x.indexOf("*");
var plus=x.indexOf("+");
var minus=x.indexOf("-");
var coma=x.indexOf(",");
var dotpos=x.lastIndexOf(".");
var neg=x.indexOf("~");
var neq=x.indexOf("!");
var b1=x.indexOf(")");
var b2=x.indexOf("(");
var b3=x.indexOf(":");
var b5=x.indexOf("?");
var b6=x.indexOf(">");
var b7=x.indexOf("<");
var b8=x.indexOf("}");
var b9=x.indexOf("{");
var b10=x.indexOf("|");
if (x==null || x=="")
{
alert("Email is mandatory");
return false;
}
if (atpos<1 || dotpos<atpos+2 || dotpos+2>=x.length || space>0 || dollar>0 || hash>0 || per>0 || or>0 || amber>0 || star>0 || plus>0 || minus>0 || coma>0 || neg>0 || neq>0 || b1>0 || b2>0 || b3>0 || b5>0 || b6>0 || b7>0 || b8>0 || b9>0 || b10>0)
{
alert("Not a valid e-mail address");
return false;
}
}
</script>
<form name="register" onsubmit="return validateForm()" action='http:\\www.google.com' method='get'>
<font face="Times New Roaman">Email Address*</font></td><td><input type='text' name='email' value='example#domain.com' onblur="if (this.value == '') {this.value = 'example#domain.com';}"
onfocus="if (this.value == 'example#domain.com') {this.value = '';}">
<input type='submit' value='submit'>
</form>

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.

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