function centermainlayer() {
		var mainstyle=document.getElementById("mainlayer").style;
		newleft=Math.round(document.body.clientWidth/2)-490;
		if (newleft>0) {
			mainstyle.left=newleft+"px";
		}
//		newtop=25;
//		mainstyle.top=newtop+"px";
	}
	window.onresize=centermainlayer;