;(function($) {
	
	$.fn.extend({
		shadow: function(deep) {
			
			if (IE6) return;
			
			return this.each(function() {
				
				var element = $(this).find(".dropshadow");
				element.removeClass("dropshadow");

				var col = deep || 4;

				var opacity = (100 - 50) / col / 100;
				var height = element.height();
				
				for (var i = 0; i < col; i++) {
					var shadow = $('<div></div>').css({
						"opacity": opacity,
						"filter": "alpha(opacity=" + (opacity * 100) + ")",
						"background-color": "#000",
						"position": "absolute",
						"width": "100%",
						"top": (i) + "px",
						"left": (i) + "px",
						"float": "left",
						"height": height + "px"
					}).addClass("dropshad-" + i);
					element.prepend(shadow);
				}

				var oldHeight = height;
					
				setInterval(function(){
					if (element.css("display") == "block") {
						var height = element.height();
						
						if (oldHeight != height) {
							for (var i = 0; i < col; i++) {
								element.find(".dropshad-" + i).height(height);
								oldHeight = height;
							}
						}
					}
				}, 200);
			});
		}
	});

})(jQuery);