function checkIt(evt) {
	evt = (evt) ? evt : window.event;
	var charCode = (evt.which) ? evt.which : evt.keyCode;
	if (charCode > 31 && (charCode < 48 || charCode > 57)) return false;
	else return true;
}

function calculatePrice() {
	var price = 0;
	var pieces = document.getElementById("pieces").value;
	var card_select = document.getElementById("card_id");
	if (pieces>0) {
		var card_id = card_select.options[card_select.selectedIndex].value;
		document.getElementById("pieces").name='xs[count]['+card_id+']';
		eval('var onePrice = price'+card_id+';');
		price = pieces * onePrice;
		rowShowHide('');
	} else {
		rowShowHide('none');
	}
	document.getElementById("priceSpan").innerHTML = formatMoney(price);
}

function rowShowHide(showhide){
	var row = document.getElementById("priceRow");
	row.style.display = showhide;
}

function formatMoney(num) {
	num = num.toString().replace(/\$|\,/g,'');
	if(isNaN(num)) num = "0";
	num = num.toString();
	for (var i = 0; i < Math.floor((num.length-(1+i))/3); i++)
		num = num.substring(0,num.length-(4*i+3))+','+ num.substring(num.length-(4*i+3));
	return num + ' HUF';
}