function calc(qty, each, total) {
    $('vals').style.visibility="hidden";
    var quantity = parseInt($(qty).value);
    if(quantity == "" || isNaN(quantity) || quantity < 1) {
	alert("Please enter a valid quantity.");
	$(qty).pulsate();
	return false;
    }
    $('vals').style.visibility="visible";
    // iterate over (sorted?) keys in pricing
    var unit_price = pricing_structure[1]; // price of an individual item
    for (min in pricing_structure) {
	if ( quantity < min) {
	    break;
	}
	unit_price = pricing_structure[min];
    }

    $(each).innerHTML = CurrencyFormatted(unit_price);
    $(total).innerHTML = CurrencyFormatted(unit_price * quantity);

    $('unitprice').value = CurrencyFormatted(unit_price);
    $('totaldollars').value = CurrencyFormatted(unit_price * quantity);
}

function CurrencyFormatted(amount)
{
    var i = parseFloat(amount);
    if(isNaN(i)) { i = 0.00; }
    var minus = '';
    if(i < 0) { minus = '-'; }
    i = Math.abs(i);
    i = parseInt((i + .005) * 100);
    i = i / 100;
    s = new String(i);
    if(s.indexOf('.') < 0) { s += '.00'; }
    if(s.indexOf('.') == (s.length - 2)) { s += '0'; }
    s = minus + s;
    return s;
}
// end of function CurrencyFormatted()