$(document).ready(function() {
	$('.rollover').hover(function(){
		$(this).attr("src", $(this).attr("src").replace("_off","_on"));
	}, function(){
		$(this).attr("src", $(this).attr("src").replace("_on","_off"));
	});
	$('.rollover').each(function(){
		$("<img>").attr("src", $(this).attr("src", $(this).attr("src").replace("_on","_off")));
	})
});