$(document).ready(function(){

	$('img.over').mouseover(function() {
		var overImg = OverImgOf($(this).attr("src"));
		$(this).attr({src : overImg});
		//confirm(overImg);

	}).mouseout(function(){
		var normalImg = NormalImgOf($(this).attr("src"));
		//confirm(normalImg);
		$(this).attr("src", normalImg);
	});	

}); 

function OverImgOf(filename){
   var re = new RegExp("(.+)\\.(gif|png|jpg)", "g");
   return filename.replace(re, "$1_over.$2");
}

function NormalImgOf(filename){
   var re = new RegExp("(.+)_over\\.(gif|png|jpg)", "g");
   return filename.replace(re, "$1.$2");
}