$(function(){
	var thisSRC = new Array;
	var thisFtype = new Array;
	var thisHSRC = new Array;
	$.each($("img.imgover"),function(i,v) {
		thisSRC[i] = $(v).attr("src");
		thisFtype[i] = thisSRC[i].substring(thisSRC[i].lastIndexOf("."), thisSRC[i].length);
		thisHSRC[i] = thisSRC[i].replace(thisFtype[i], "_ov"+thisFtype[i]);
		$(v).mouseover(function(){
			$(v).attr("src", thisHSRC[i]);
		});
		$(v).mouseout(function(){
			$(v).attr("src", thisSRC[i]);
		});
	});
});