function zetArceer(item) {
	document.getElementById(item).style.display= 'block';
	}

	function verwijderArceer(item){
	document.getElementById(item).style.display= 'none';
	}


	window.onload = Init;
	
	function Init()
	{
		fixH("kolom_links","kolom_rechts",650);
	}
	
	function fixH(one,two,min_h) {
		if (document.getElementById(one)) {
		var lh=document.getElementById(one).offsetHeight;
		var rh=document.getElementById(two).offsetHeight;
		var nh = Math.max(lh, rh, min_h);
		document.getElementById(one).style.height=nh+10+"px";
		document.getElementById(two).style.height=nh+10+"px";
		}
	}