A submit button is only going to be a successful control if it is used to submit the form (and even then only if it has a name and a value … which yours does not).
If you want submit=submit
in your form data when you submit the form with JavaScript, then don't use a submit button to put that data in the form in the first place. Use a hidden input.
<input type="submit">
<input type="hidden" name="submit" id="submit" value="submit">
Then you have two other problems.
First, submit is a method of form elements, not inputs. So you need to change your script to call the right element.
<script>document.getElementById('submit').form.submit();</script>
Second, if a form has a control called submit
then that will clobber the submit
method. So you need to get one from a different form (not supported in old versions of Internet Explorer):
<script>
var form = document.getElementById('submit').form;
var submit_method = document.createElement("form").submit;
submit_method.call(form);
</script>