function calcResult(form)

{
        if ((form.years.value == null || form.years.value.length == 0) ||
            (form.interest.value == null || form.interest.value.length == 0) ||
            (form.amount.value == null || form.amount.value.length == 0))
	{
            return;
        }
       var payments = form.years.value;
       payments  = payments * 12;
        if (!checkEntry(form.years, 1, 40, "# of Years") ||
            !checkEntry(form.interest, .001, 99, "Interest") ||
            !checkEntry(form.amount, 100, 10000000, "Amount"))
	{
            return;
        }
        var i = form.interest.value;
        if (i > 1.0)
	{
            i = i / 100.0;
            
        }
        i /= 12;
        var pow = 1;
        for (var j = 0; j < payments; j++)
            pow = pow * (1 + i);
        var k = 0.1
        k /= 12;
        var kow =1;
        for (var l =0; l < payments; l++)
            kow =kow * (1 + k);
        form.payment.value = (form.amount.value * pow * i) / (pow - 1);
        form.payment.value = Math.round(form.payment.value * 100) / 100;
        form.total.value = Math.round(form.payment.value * 12 * form.years.value * 100 ) / 100;    
        form.interestonly.value = Math.round(form.amount.value * i *100) /100;
        
        form.payment10.value=(form.amount.value * kow * k) / (kow - 1);
        form.payment10.value = Math.round(form.payment10.value * 100) / 100;
        form.total10.value = Math.round(form.payment10.value * 12 * form.years.value * 100 ) / 100;
        form.interestonly10.value = Math.round(form.amount.value * k *100) /100;
}

function checkEntry(input, min, max, msg)
{
        msg = msg + " field has invalid data: " + input.value;
        var str = input.value;
        for (var i = 0; i < str.length; i++)
	{
            var ch = str.substring(i, i + 1);
            if ((ch < "0" || "9" < ch) && ch != '.')
	    {
                alert(msg);
                return false;
            }
        }
        var num = 0 + str;
        if (num < min || max < num)
	{
            alert(msg + " not in range [" + min + ".." + max + "]");
            return false;
        }
        input.value = str;
        return true;
}

function computeField(input)

{
        if (input.value != null && input.value.length != 0) {
            // input.value = input.value.replace(/\,/g,"");
            input.value = input.value.replace(/[^0-9\.]/g,"");
            //input.value = "" + eval(input.value);
        }
        calcResult(input.form);
}

function clearForm(form)
{
        form.years.value = "";
        form.interest.value = "";
        form.amount.value = "";

}