$(function(){
	$("img.over").mouseover(function(){
		$(this).attr("src",$(this).attr("src").replace(/^(.+)(\.[a-z]+)$/, "$1_on$2"))
	}).mouseout(function(){
		$(this).attr("src",$(this).attr("src").replace(/^(.+)_on(\.[a-z]+)$/, "$1$2"));
	}).each(function(){
		$("<img>").attr("src",$(this).attr("src").replace(/^(.+)(\.[a-z]+)$/, "$1_on$2"))
	})
})