<!-- Hide the script from old browsers --

// <script language="LiveScript">
    // JavaScript Loan Calculator
    // based on a demo by Netscape Communications, Inc.

    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 computeField(input) {

        if (input.value != null && input.value.length != 0)

            input.value = "" + eval(input.value);

        computeForm(input.form);

    }

    function computeForm(form) {

        if ((form.payments.value == null || form.payments.value.length == 0) ||

            (form.interest.value == null || form.interest.value.length == 0) ||
            
            (form.down.value == null || form.down.value.length == 0) ||

            (form.principal.value == null || form.principal.value.length == 0)) {

            return;

        }

        if (!checkNumber(form.payments, 1, 480, "# of payments") ||

            !checkNumber(form.interest, .001, 99, "Interest") ||
            
            !checkNumber(form.down, 100, 10000000, "Down") ||

            !checkNumber(form.principal, 100, 10000000, "Principal")) {

            form.payment.value = "Invalid";

            return;

        }

        var i = form.interest.value;
  
        if (i > 1.0) {

            i = i / 100.0;

            form.interest.value = i;

        }

        i /= 12;

		
		var dn = form.down.value;

        var pow = 1;

        for (var j = 0; j < form.payments.value; j++)

            pow = pow * (1 + i);

        form.payment.value = ((form.principal.value - dn) * pow * i) / (pow - 1)
        form.payment.value = Math.floor(form.payment.value*100)/100
        
    }

    function clearForm(form) {

        form.payments.value = "";

        form.interest.value = "";
        
        form.down.value = "";

        form.principal.value = "";
        
    }
//end hide-->


