function resize() {
	var bodyE   = document.getElementsByTagName('body')[0];
	var centerH = document.getElementById('maincolumn'     ).offsetHeight;
	var leftH   = document.getElementById('leftcolumn'  ).offsetHeight;
	var height = Math.max(centerH,leftH,bodyE.clientHeight - 300);

	document.getElementById('maincolumn'   ).style.height =  height    +"px";
	document.getElementById('leftcolumn'     ).style.height = (height+20)+"px";
}