//©2011 Bad Math Inc. (http://www.badmath.com/)
jQuery.fn.imageRollover = function() {

	return this.each(function() {
		$(this).each(function() {
			var overlay = $(this).children('img').attr('src').replace('.png','-on.png');
			$(this).append($('<img/>')
				.css('display','none')
				.css('position','absolute')
				.css('left',0)
				.css('top',0)
				.attr('src',overlay)
				.addClass('imageRollover')
			);
			$(this).mouseenter(function() {
				 $(this).children('.imageRollover').fadeIn(300);
			});
			$(this).mouseleave(function() {
				 $(this).children('.imageRollover').fadeOut(300);
			});
		});
	});

};