function equalHeight(group) {
		tallest = 0;
		group.each(function(c) {
			thisHeight = c.offsetHeight;
			if(thisHeight > tallest) {
				tallest = thisHeight;
			}
		}
	);
	group.invoke("setStyle", {height: tallest + 'px'}) 
}

Event.observe(window, 'load', function() { // respecter ordre du flux ;)
	equalHeight($$(".product-name"));
	equalHeight($$(".infobox"));
	equalHeight($$(".block-middle"));
	equalHeight($$(".equalize"));
});