function subMenu(layer, menu, visible) { 
	var posX = $("#"+menu).offset().left ;
	var posY = $("#"+menu).offset().top + 17;
	if(visible == true) {
		document.getElementById(layer).style.display="block";	
		document.getElementById(layer).style.left = posX + "px";
		document.getElementById(layer).style.top = posY + "px";
	} else {
		document.getElementById(layer).style.display="none";	
	}
}