function Menu(pageID,parentID,siteID)
{
	//Iterates over all menuitems (e.g #menu ul li.menuitem)
	$$(".menuitem").each(function(menuitem,i) {
		//If the current page is among the menu items
		if(menuitem.id=='li'+pageID) {
			menuitem.getChildren().each(function(child,j) {			
				if(child.getTag() == 'ul') {
					child.setStyle('display','block');
				}
			});
			menuitem.addClass("selected");				
		}
		//If the current parent page is not the startpage, and the current parent page is among the menu items
		else if((parentID != siteID) && menuitem.id=='li'+parentID) {
			menuitem.getChildren().each(function(child,j) {			
				if(child.getTag() == 'ul') {
					child.getChildren().each(function(grandchild,k) {
						if(grandchild.getTag() == 'li') {
							if(grandchild.id == 'li'+pageID)
								grandchild.addClass('selected');
							child.setStyle('display','block');		
						}	
					});
				}
			});
			menuitem.addClass("selected");
		}
	});
}