function ini_rollover() {
	var image_cache = new Object();
	$("img.swap").each(function(i) {
	var imgsrc = this.src;
	var dot = this.src.lastIndexOf('.');
	var imgsrc_over = this.src.substr(0, dot) + '_over' + this.src.substr(dot, 4);
	image_cache[this.src] = new Image();
	image_cache[this.src].src = imgsrc_over;
	$(this).hover(
		function() { this.src = imgsrc_over; },
		function() { this.src = imgsrc; });
	});
}

$(document).ready(ini_rollover);