You cannot do this because of web browser's same origin policy.
But you can use a workaround with the blur event and mouseover/mouseout events. That's how works my iframeTracker jQuery plugin, designed to track clicks on iframes : https://github.com/finalclap/iframeTracker-jquery
Here is an example :
jQuery(document).ready(function($){
$('.iframe_wrap iframe').iframeTracker({
blurCallback: function(){
// Do something when iframe is clicked (like firing an XHR request)
}
});
});
Enjoy !