title: Event to know when a form in an iFrame has been submitted
body: <p>Ok so I have an iframe on the Contact page of my website. </p>
  
  <p>The src of the iframe points to another file containing a Google Docs form. </p>
  
  <p>Once the Google docs form is submitted, the page is redirected to a Google page saying that  "your response has been recorded". </p>
  
  <p>I have this form inside an iframe so that it doesn't redirect viewers away from my entire site, but instead only the iframe document is redirected.</p>
  
  <p>This all works fine, But I want to show my own message instead of the Google "your response has been recorded". </p>
  
  <p>To do this, basically I want to know when the iframe has been redirected and/or (preferably) the form has been submitted.</p>
  
  <p>Things i've tried...</p>
  
  <ul>
  <li><p>onhaschange="" inside the iframe element</p></li>
  <li><p>onsubmit="" inside the form element (which is in the iframe src file)</p></li>
  </ul>
  
  <p>Any other ideas?</p>