var buffer = 20; //scroll bar buffer
var iframe = document.getElementById('ifm');
function pageY(elem) {
return elem.offsetParent ? (elem.offsetTop + pageY(elem.offsetParent)) : elem.offsetTop;
}
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';
}
// .onload doesn't work with IE8 and older.
if (iframe.attachEvent) {
iframe.attachEvent("onload", resizeIframe);
} else {
iframe.onload=resizeIframe;
}
window.onresize = resizeIframe;
