function adCalc(form) {
var ok = 0;
var price = document.form.price.value;
var units = document.form.units.value;
var cost = document.form.cost.value;


if (price != "" && units != "")  { 
	document.form.cost.value = (price * units);
	document.form.cost.value = formatCurrency(document.form.cost.value) ;
	 ok++; 
}




}

function formatCurrency(num) {
	num = num.toString().replace(/\$|\,/g,'');
	if(isNaN(num))
	num = "0";
	sign = (num == (num = Math.abs(num)));
	num = Math.floor(num*100+0.50000000001);
	cents = num%100;
	num = Math.floor(num/100).toString();
	if(cents<10)
	cents = "0" + cents;
	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 (((sign)?'':'-') + '$' + num + '.' + cents);
}