$(function(){
	$('.rollOver').each(function(){
		var defaultImage = $(this).attr('src');
		var rollOverImage =
			defaultImage.replace(/(.*)\.(png|gif|jpe?g)/,'$1_mouseover.$2');
		(new Image()).src = rollOverImage;
		$(this).mouseover(function(e){
			$(this).attr({src:rollOverImage});
		}).mouseout(function(e){
			$(this).attr({src:defaultImage});
		});
	});
});