I believe I have a similar problem to this person:
JavaScript: Detect form submission completion
I have a form in an iframe. When the form completes an http post, i want to capture the returning data and do something with it. Is there an event handler to detect when a form in an iframe completes an http post?
If a new page is being loaded (a non-AJAX submit) you can hook into the Iframe’s
onloadevent for this purpose.