iframe javascript redirect

Hi,

I created a poll using a form builder (survey monkey) and would like to have users be redirected to another page after they click submit. Unfortunately, the entire poll is in an iframe and I cannot pull the submit button very easily. I was wondering if there was any way to detect the submit button within the iframe and inject an "onclick="location.href"" when the button is pressed.

Thank you!!!

ps: All I have of the form is the link.

This is easy *IF* the page inside the <iframe> is coming from the SAME SITE as the page that contains the <iframe>. Otherwise, it is only possible if you have access to the server where the <iframe> comes from and can make some minor changes to the code there.