I have an iframe:

<iframe id="myiframe" src="<?php echo $json['url']; ?>"style="position:fixed; top:0; left:0; bottom:0; right:0; width:100%; height:100%; border:none; margin:0; padding:0; overflow:hidden; z-index:999999;">
    <p>Your browser does not support iframes.</p>
  </iframe>

it can have random src(on one domain) but that domain will redirect on different sites. For example src is example.com/generated path with parameters and that url is redirecting to google.com. Can I catch new url of iframe (google.com) and if (it == 'google.com') { alert(1); } ?