function mainmenu(){
//$("#main-menu ul ").css({display: "none"}); // Opera Fix
	$("#main-menu li").hover(function(){
		$(this).find('ul:first').css({visibility: "visible",display: "none"}).slideDown(400);
	},function(){
		$(this).find('ul:first').css({visibility: "hidden"});
	});
} 
 
$(document).ready(function(){					
	mainmenu();
});