(function($) {
	var settings;
	
	$.shadow = function(callerSettings) {
		settings = $.extend({
			shadowImageSrc: '/images/fallout.png',
			heightElementID: 'mainStructure', 
			width: '100%',
			leftCoordinate: 0,
			topCoordinate: 0,
			darkness: 1
		}, callerSettings || {} );
	
		var height = $('#' + settings.heightElementID).height();
		for (i = 0; i < settings.darkness; i++) {
			var element = $('<div>')
				.attr('id', '__shadow')
				.css({
					position: 'absolute',
					width: settings.width,
					height: height,
					'z-index': 998,
					left: settings.leftCoordinate,
					top: settings.topCoordinate,
					background: ('url(' + settings.shadowImageSrc + ') repeat left top')
				});
				
			if ($.browser.msie && $.browser.version == "6.0") {
				element.css({
					background: 'none',
					filter: ("progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" + settings.shadowImageSrc + "',sizingMethod='scale')")
				});
			}
			
			$(document.body).prepend(element);	
		}
	}
	
	$.unshadow = function() {
		$('#__shadow').remove();
	}
	
})(jQuery);