JavaScript code to be run prior to the submission of the form.
Blank. No JavaScript is run.
Any valid JavaScript function, or JavaScript code followed by a semicolon (;).
If you want to execute the presubmit JavaScript only, without running the JavaScript that submits the request (thus canceling the onclick event), append return false; to your presubmit JavaScript.
The following example shows a message box:
The following example shows a message box and cancels the submit JavaScript:
