Develop Reference

HTML/JS Form being submitted twice

I am using node.js/express to create a webpage.
I currently have a form with some input and a submit button which is trigger by the click of another button currently on the page
This is the code for my form:
<form name= "form" id="form-id" action="http://localhost:1337/process_post" method="POST">
<input type="hidden" name="hiddentext" id="textarea"/>
<input hidden type="submit" name="submitbutton" id="submit_button"/>
</form>
This is my button (which triggers the submit for the form to be clicked during the onclick event)
<INPUT type="button" id="button-id" value="Save" onclick="this.disabled=true;load_page('form-id')" />
This is my JS script to click the submit button
function load_page(formId){
document.getElementById("submit_button").click();
}
The issue I have is that the form is being submitted twice. I am unsure why this happens and how to fix the issue. Any tips?

You need to return false in your onclick attribute so as to prevent the default action, which is to submit the form (which you're already doing). Like this:
<INPUT type="button" id="button-id" value="Save" onclick="this.disabled=true;load_page('form-id');return false;" />

form is submit but values are not passing

When I submit form by using below function it is submitting but values are not passed through this function. I use all functions but nothing found:
document.getElementById("postad").submit();
Form is given below.
<form action="register.php" id="postad" method="post">
<input class="textfield2" type="text" id="post_title" style="width:640px;" placeholder="Ad Title" onBlur="check('post_title')" />
<input class="button" type="button" name="save" value="Publish" onclick="send();" />
</form>

Your form contains two form controls. Neither will be a successful control (i.e. one that appears in the submitted data), but for different reasons.
Only form controls with name attributes can be successful. Your text input doesn't have a name. (It also doesn't have a default value, so you need to type in it first).
Buttons can only be successful if they are the submit button used to submit the form. Your button isn't a submit button and you use JavaScript to submit the form.

There is no name attribute in your input text fields
<input name="post_title" class="textfield2" type="text" id="post_title" style="width:640px;" placeholder="Ad Title" onBlur="check('post_title')" />
.........^

Submit form with Javascript doesn't work

I have a simple form for uploading a file. If I use an ordinary submit button, everything works as expected:
<form id="mainform" method="post" action="/" enctype="multipart/form-data">
...
<input type="submit" id="submit" value="Analyze File"/>
</form>
But if I change it to an ordinary button and use Javascript to submit the form, nothing happens:
<input type="button" id="submit" value="Analyze File" onclick="document.getElementById('mainform').submit()"/>
I verified that the onclick handler really is getting called, and looking up the form works correctly. For example, if I change it to onclick="alert(document.getElementById('mainform').action)", the alert comes up as expected and shows the target URL of the form. But for some reason, the call to submit() simply doesn't submit the form.

The issue is your submit button. Its id is submit, which means that document.getElementById("mainform").submit represents the button with ID of submit, not the submit function.
You just need to change the ID for that button, and you're all good.

You have a naming conflict between the .submit() method and the:
<input type="submit" id="submit" value="Analyze File"/>
By having that id, a reference to it is being assigned to the submit property of the <form>, which replaces the method.
If you rename the <input>, you should be able to .submit() as expected:
<input type="submit" id="mainform_submit" value="Analyze File"/>

multiple submit buttons on same form with onsubmit function

I have 3 sumbit buttons in myform and i need different 3 actions based on which buttton it clicked. so i need to write javascript function to do the same. how i can get to know in javascript which button is clicked.
Javascript:
<script type="text/javascript" language="javascript">
function submitform(){
//do something
}
HTML:
form name="myform" method="get,post" onsubmit="return submitform();"
input type="submit" name="submit" value="Home"
input type="submit" name="submit" value="Reschedule"
input type="submit" name="submit" value="Cancel"
Any help will be appreciated

Edit:
You could also have a hidden input which tells you which button was pressed, then handle it on the server. When a button is clicked it will change that input before submitting.
<input type="submit" onclick="javascript:document.getElementById('submitClicked').value='forward';return true;" id="linkName" value="Forward" />
<input type="submit" onclick="javascript:document.getElementById('submitClicked').value='back';return true;" id="back" value="Back" />
Demo: http://jsfiddle.net/Homeliss/vperb/
Note: the demo uses jquery to show a message instead of posting the form, but that is just for demo purposes. The solution is plain javascript

In modern browsers, you can use the submitter property of a SubmitEvent.
function submitForm(submitType)
{
switch (submitType)
{
case 'Submit 1':
console.log('Submit 1');
break;
case 'Submit 2':
console.log('Submit 2');
break;
}
return false;
}
<form onsubmit="return submitForm(event.submitter.value)">
Name: <input name="name" required /><br />
<div>
<input type="submit" value="Submit 1" />
<button type="submit" value="Submit 2">Submit 2</button>
</div>
</form>

If you could use jQuery, then this could be much easier.
One solution however would be to remove the submitform() from the form and add it to the onclick event of each of your submit buttons. This way, you can alter it to pass a parameter denoting which button called it.
Good luck.

we can submit a form once in html pages. So we use only one submit button in a form. But for calling more functions we can use onClick event and input type should be button.

I have a question. is there any other input field inside your form?
If there is another field such as text field, which buttons action will be call when we press Enter inside the text field?
My suggestion is this:
<form name="myform" method="get,post" onsubmit="return false;">
<input type="button" value="Home" onclick="submitform(1)" />
<input type="button" value="Reschedule" onclick="submitform(2)" />
<input type="button" value="Cancel" onclick="submitform(3)" />
</form>
in this code, user must click on a button to submit the form and pressing the enter will not cuse to doing any action.

html button v.s. html submit?

I have an input text box and a search submit button, and when user clicks the Search submit button, I want to redirect user to url http://testsearch/results.aspx?k=<value of text box k>, for example, if user put "StackOverflow" into text box and then clicks the search button, I want to redirect user to the following page,
http://testsearch/results.aspx?k=StackOverflow
I find when I use button for Search button, it works (see below source codes),
<input type="text" id="k" name="k" />
<input type="button" id="Go" value="Search" onclick="location.href = 'http://somemachine/Search/results.aspx?k='+document.getElementById('k').value;"/>
but when I use submit for Search button, it does not works (see below source codes), why?
<input type="text" id="k" name="k" />
<input type="submit" id="Go" value="Search" onclick="location.href = 'http://somemachine/Search/results.aspx?k='+document.getElementById('k').value;"/>
thanks in advance,
George

You can even use the submit button this way:
<input type="submit" id="Go" value="Search" onclick="document.location='http://testsearch/results.aspx?k=StackOverflow'; return false;" />
Semantically submit button is used to submit forms not redirect pages. You should use normal button type for this. However as i showed you can use the submit button too but that is not semantic i think.
The below line prevents the form from being submitted.
return false;
That is what you are missing in your code :)
Thanks

<button>-elements and <input type="button"/> don't do anything by default, unless you tell them to do something with Javascript.
<input type="submit"/> will submit the form it is in.
So, if <input type="submit"/> won't work, you got it probably not in the <form/>-element itself.

If that's the only field in your form, simply set the form's method to "get" and it'll work.
<html>
<body>
<form action="http://localhost/mytest" method="get" >
<input type="text" id="k" name="k" />
<input type="submit" id="Go" value="Search" />
</form>
</body>
</html>

<button> means "put a button in the page and do whatever the onclick event says". So if you don't write an onclick handler the page doesn't do nothing.
If you use submit is ok, because you want to redirect to another page.
If you want to use button anyway you can do this way:
<script>
function doTheSearch() {
// do the submit mannually
document.getElementById('myForm').submit();
}
</script>
<form id="myForm" action="results.aspx">
<input type="text" id="k" name="k" />
<input type="button" id="Go" value="Search" onclick="doTheSearch();" />
</form>
Warning: submit button with onclick
If you have a submit button (inside a form, it is, a working submit button) with an onclick event, some browsers will:
1) execute onclick
2) execute submit
your onclick tries to redirect but the submit button wins.
If you want to avoid it you have some options:
a) change submit button to normal button
b) avoid the submit thing (add onsubmit="return false;" to form element)
c) use the submit procedure (form action="..." method="get", no onclick event), the browser will be happy and you can control the submit in the onsubmit event (you can cancel it or not).

make sure you got the input's in a form tag with a GET method:
<form action='http://testsearch/results.aspx' method='GET'>
... inputs
</form>

If I'm understanding correctly, it is not working because it is not in a form tag. If you put it in a form tag with method="get" it should work. The button works because it does not have to be in a form.