<script type=“text/javascript”> var buffer = 0; scroll bar buffer var iframe = document.getElementById('ifm'); function pageY(elem) { return elem.offsetParent ? (elem.offsetTop + pageY(elem.offsetParent)) : elem.offsetTop; } var buffer = 1; scroll bar buffer function resizeIframe() {

  var height = window.innerHeight || document.body.clientHeight || document.documentElement.clientHeight;
  height -= pageY(document.getElementById('ifm'))+ buffer ;
  height = (height < 0) ? 0 : height;
  document.getElementById('ifm').style.height = height + 'px';

}

.onload doesn't work with IE8 and older. if (iframe.attachEvent) { iframe.attachEvent(“onload”, resizeIframe); } else { iframe.onload=resizeIframe; } window.onresize = resizeIframe; </script>