function resize_iframe()
{

	var height=window.innerWidth;//Firefox
	if (document.body.clientHeight)
	{
		height=document.body.clientHeight;//IE
	}
	//resize the iframe according to the size of the
	//window (all these should be on the same line)
	document.getElementById("main").style.height=parseInt(height);
	document.getElementById("main").offsetTop-8)+20;
}

// this will resize the iframe every
// time you change the size of the window.
window.onresize=resize_iframe;