title: Capture click of Pay Now button in Paypal iFrame (cross domain)
body: <p>I have a payment system using Paypal's payflow where they send me an iFrame to render.  I would like to capture when the "Pay Now" button has been clicked so I can hide a "Cancel" button on my page while the transaction is processing.</p>
  
  <p>I have tried the usual jQuery:</p>
  
  <p><code>$("#iFrame .button").click(function(){});</code></p>
  
  <p>and</p>
  
  <p><code>$("#iFrame").contents().find("input[type='button']")</code></p>
  
  <p>but nothing is working.  I get the error:</p>
  
  <p>Uncaught DOMException: Failed to read the 'contentDocument' property from 'HTMLIFrameElement': Blocked a frame with origin "<a href="http://localhost" rel="nofollow">http://localhost</a>" from accessing a cross-origin frame</p>
  
  <p>Any ideas on how I can capture the click?</p>