How send a form with Javascript when input name is “submit”?

Question

Question: How can you send a form with Javascript if one form input has the name submit?

Background: I am redirecting the user to another page with a hidden HTML form. I cannot change name on the (hidden) inputs, since the other page is on another server and the inputs need to be exactly as they are. My HTML form looks like this:

<form id="redirectForm" method="post" action="http://www.example.com/">
  <input name="search" type="hidden" value="search for this" />
  <input name="submit" type="hidden" value="search now" />
</form>

I use the following javascript line to send the form automatically today:

document.getElementById('redirectForm').submit();

However, since the name of one input is "submit" (it cannot be something else, or the other server won't handle the request), document.getElementById('redirectForm').submit refers to the input as it overrides the form function submit().

The error message in Firefox is: Error: document.getElementById("requestform").submit is not a function. Similar error message in Safari.

Answer 1

Worth noting: It's often a lot easier to just change the input name to something other than "submit". Please use the solution below only if that's really not possible.

You need to get the submit function from a different form:

document.createElement('form').submit.call(document.getElementById('redirectForm'));

If you have already another <form> tag, you can use it instead of creating another one.

Answer 2

Use submit() method from HTMLFormElement.prototype:

HTMLFormElement.prototype.submit.call(document.getElementById('redirectForm'));