Got a form that you keep getting multiple submissions from?
I've found that in most cases its because people are impatient and click the submit button repeatedly until they get a response. The unfortunate result is that you receive multiple copies of the same form.
This little bit of JavaScript disables the submit button as soon as it is clicked for the first time and prevents the user sending their form multiple times. The script now also changes the word "submit" to "thanks" as an extra indication that the form has been sent.
<form onsubmit="JavaScript:this.subbut.disabled=true;this.subbut.value='Thanks';">
<input type="submit" name="subbut">
</form>
so you have to add:
onsubmit="JavaScript:this.subbut.disabled=true;this.subbut.value='Thanks';"
to your <FORM> tag and you need to make sure that the name of your submit button matches
i.e. <input type="submit" name="subbut">
Test the script on this button. (as soon as you click it, it should be disabled)