presubmit_js
JavaScript code to be run prior to the submission of the form.
Default value
Blank. No JavaScript is run.
Valid values
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.
Example
The following example shows a message box:
The following example shows a message box and cancels the submit JavaScript:
