iframe autoresize

gistfile1.js

<script>
// Parent
  function onMessage (event) {
    if (event.source != document.getElementById('iframe').contentWindow) return;
    eval('var message = ' + event.data);
    resizeIframe(message.height);
  }
  if (typeof(window.attachEvent) != "undefined") {
    window.attachEvent('onmessage', onMessage);
  } else if (typeof(window.addEventListener) != "undefined") {
    window.addEventListener('message', onMessage, false);
  }

  function resizeIframe(height) {
    document.getElementById("iframe").style.height = parseInt(height) + 60 + 'px';
  }

  resizeIframe(2000);// Height for <=IE7
</script>


<script>
// iframe
function _postMessage() {
    var message = '{"height":"' + document.body.offsetHeight + '"}';
    window.parent.postMessage(message,"*");
}

jQuery(document).ready(function(){
  if (typeof(window.parent.postMessage) != 'undefined') {
    _postMessage();
    setInterval(_postMessage, 1000);
  }
});
</script>