How to call javascript function/write script inside PHP echo

Question

I have written piece of code, below is the code

<script type="text/javascript">
function submitform()
{
 document.myform.action='http://mysite/index.php';
 document.myform.submit();
}
</script>
<?php
if(isset($_POST['submit_details']))
{
 echo "<script typ=javascript> submitform();</script>";
}
?>
<form id="myform">
 ------
 ------
<input type="submit" name="submit_details">
</form>

when i try to submit the form , it gives me error document.myform is undefined, how to solve this error

• Herbert: There's a lot wrong with your code as written. You have syntax errors in your PHP code. You're using Javascript to do something the browser will do using <form action="http://mysite/index.php" method="GET"> and if this is index.php, then your PHP will automatically submit the form again... and again... and again...

Answer 1

document.myForm is undefined when you are calling the script because it is being run before the form element has been received by the browser. You need to put the script after the form tag, or use a document.onload event handler (or similar).

(Although quite why you want to automatically and immediately submit a form by JS without your user doing anything is beyond me.)

Answer 2

If that's literally your code, then it's got syntax errors up the wazoo.

Try:

<?php if (isset($_POST['submit_details'])) { ?>
 <script type="text/javascript">submitForm();</script>
<?php } ?>

• n92: i added the above code at the end of the page, the form is getting submitted but the form values are empty.form is submitting has an empty form

Answer 3

Try moving the script to the bottom of the page, or better, listen to the window.onload event. When the script is loaded by the browser, the DOM hasn't finished loading and cannot find document.myForm yet.

Answer 4

Why dont you just put the javascript submit inside the input like so?

<input type="submit" name="submitdetails" onclick="javascript:submitform();" />

Then use $post with jquery to run the page.

• Mike Samuel: The javascript: is superfluous.
• Juan Gonzales: By doing this, he wouldn't have to call the function in php. I thought it would be more efficient.
• daiscog: You don't need to add javascript: inside on* attributes of elements. Suggesting he add jQuery to his page is overkill - why include a whole JS library to do something simple that can be done in a quick, easy, cross-browser manner?
• Mike Samuel: The value of an onclick attribute is not a URL, so you don't need the javascript protocol. <input onclick="submitform()"> is just fine. Not that the OP needs javascript -- they could just put the action in the form.
• Juan Gonzales: good to know. also I only suggested jQuery because I assumed this probably isn't the only form on his page, as well as functions, but I do understand what your telling me. Thanks!