$( document ).ready(function() {
	$( "ul#menu li" ).mouseenter(function(){
		var _elem = this;
		var elem = $( _elem );
		if ( elem.hasClass( "activated" ) )
			return false;
		elem.find( "ul" ).slideDown( 500 );
		elem.addClass( "activated" );
	}).mouseleave(function(){
		var _elem = this;
		var elem = $( _elem );
		elem.find( "ul" ).slideUp( 500, function() {
			elem.removeClass( "activated" );
		});
	});
});