function setOverlay(html) {
	mainx = YAHOO.util.Dom.getX("main");
	mainw = (YAHOO.util.Dom.getStyle("main","width")).replace("px","");
	overlayw = (YAHOO.util.Dom.getStyle("overlay1","width")).replace("px","");
	x = (mainx + (mainw / 2)) - (overlayw / 2);
	
	mainy = YAHOO.util.Dom.getY("main");
	mainh = (YAHOO.util.Dom.getStyle("main","height")).replace("px","");
	overlayh = (YAHOO.util.Dom.getStyle("overlay1","height")).replace("px","");	
	y = (mainy + (mainh / 2)) - (overlayh / 2);
	html = "<a onclick=\"hideOverlay()\">close</a><br/>" + html;
	document.getElementById("overlay1").innerHTML = html;
	YAHOO.util.Dom.setX("overlay1",x);
	YAHOO.util.Dom.setY("overlay1",y);
	YAHOO.util.Dom.setStyle("overlay1","visibility","visible");
}

function hideOverlay() {
	YAHOO.util.Dom.setStyle("overlay1","visibility","hidden");		
}