document.observe('dom:loaded', function() {
	var items = [];
	var display = $('summa');
	var f = function() {
		var summa = items.inject(0, function(s, i) { return s + i.summa(); });
		display.update( stwUtils.number.formatCommas(Math.round(summa * 100)/100) );
	}

	$$('.price').each(function(td){
		var item = {
			'price': parseFloat( td.readAttribute('stwPrice') ),
			'counter': td.up('TR').down('input[type=text]'),
			'summa': function() {
				return item.price * parseFloat(item.counter.value ? item.counter.value.replace(',', '.') : 0);
			}
		};
		item.counter.observe('change', f);
		items.push(item);
	});
});