document.observe('dom:loaded', function() {
	var images = $$('.matrix td img');

	images.each(function(item) {
		item.src_norm = item.src.replace(/_over/, '');
		item.src_over = item.src_norm.replace(/((?:_\d+x\d+)?\.\w+)$/, '_over$1');

		item.onmouseover = function() {
			this.src=this.src_over;
		}
		item.onmouseout = function() {
			this.src=this.src_norm;
		}
		item.onmouseup = item.onmouseout;
	})
})