
<!-- Beginning of JavaScript Applet -------------------
    

    function checkNumber(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 computeForm(form) 
    {


    Item = form.payments.selectedIndex;
    payments = form.payments.options[Item].text

    Item = form.interest.selectedIndex;
    interest = form.interest.value


    if ( form.principal.value.length == 0 && form.pay.value.length == 0 )
      {
       return false;
      }

    if ( form.principal.value.length > 0 )
      {
        if (!checkNumber(form.principal, 100, 10000000, "Principal"))
	   {
           return false;
	   }

	var tpay = payments * 12;
        var i = interest;
	i /= 12;
        var pow = 1;
         for (var j = 0; j < tpay; j++)
	    {
              pow = pow * (1 + i);
	    }
       form.pay.value = (form.principal.value * pow * i) / (pow - 1);

    out="principal: " + form.principal.value + "  " + form.principal.value.length  + " payments: " + payments + " interest: " + interest + " payments: " + form.pay.value + " " + form.pay.value.length ; 

//    alert(out);
      }
      else
      {
        if (!checkNumber(form.pay, 1, 1000000, "Payments"))
	   {
           return false;
	   }

	var tpay = payments * 12;
        var i = interest;
	i /= 12;
        var pow = 1;
         for (var j = 0; j < tpay; j++)
	    {
              pow = pow * (1 + i);
	    }
        form.principal.value = (pow - 1) * (form.pay.value)/( pow * i);
        }

money = "" + .01* Math.round(100*(form.principal.value * pow * i) / (pow - 1));
dec = money.indexOf(".");
dollars = money.substring(0,dec); 
cents = money.substring(dec+1,dec+3);
cents = (cents.length < 2) ? cents + "0" : cents;
money = dollars + "." + cents;
form.pay.value = money;

     return true;
      }


    function clearForm(form) {
//        form.payments.value = "";
//        form.interest.value = "";
        form.principal.value = "";
        form.pay.value = "";
    }
//-->