function showLayer(id){
 	 hideAll();
 	 a=document.getElementById(id);
 	 a.style.visibility = "visible";
}
function restoreLayer(id){
 	 showLayer(id);
 	 window.setTimeout("restoreLayer('"+id+"')",5000);
}
function hideLayerH(id){
 	 a=document.getElementById(id);
 	 a.style.visibility = "hidden";
}
function hideAll(){
	hideLayerH('sub1');
	hideLayerH('sub2');
	hideLayerH('sub3');
}