$(document).ready(function() { 
	$("#main-menu li").hover(function(){ 
		this._w = this.offsetWidth;
        $(this).find('ul:first').css({visibility: "visible",display: "block", left: this._w + "px"}).show("slow"); 
        },function(){ 
        $(this).find('ul:first').css({visibility: "hidden",display: "none"}).hide("fast"); 
        }); 
});