$(function() {
	var CLASS_NAME = "btn";
	var SUFFIX	   = "_o";

	$("img."+CLASS_NAME+", input."+CLASS_NAME).each(function() {
		var e = $(this);

		e.attr("orig_src", e.attr("src"));
		e.attr("ol_src", e.attr("src").replace(/(?:_sel)?\.(gif|jpg|png)/, SUFFIX+'.$1'));

		document.createElement("img").src = e.attr("ol_src");

		e.hover(
			function() { this.src = $(this).attr("ol_src"); },
			function() { this.src = $(this).attr("orig_src"); }
		);
	});
});