$(document).ready(function () {
	function pageY(elem) {
		return elem.offsetParent ? (elem.offsetTop + pageY(elem.offsetParent)) : elem.offsetTop;
	}

	var buffer = 5; //scroll bar buffer
	function resizeIframe() {
		var height = document.documentElement.clientHeight;
		height -= pageY(document.getElementById('ifm')) + buffer;
		height = (height < 0) ? 0 : height;
		document.getElementById('ifm').style.height = height + 'px';
	}

	document.getElementById('ifm').onload = resizeIframe;
	window.onresize = resizeIframe;
});