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 KeyPressMsg(e,str)
	{
		if(e.keyCode==46 && str.indexOf('.')==-1)
		{
			
		}
		else if (e.keyCode<48 || e.keyCode>57){
			window.event.keyCode = 0;
		}
		
	}
    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.principal.value == null || form.principal.value.length == 0)) {
            return;
        }
        if (!checkNumber(form.payments, 1, 480, "'Number of Months'") ||
            !checkNumber(form.interest, .001, 99, "'Interest Rate'") ||
            !checkNumber(form.principal, 100, 10000000, "'Amount Financed'"))
                                 {
            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 pow = 1;
        for (var j = 0; j < form.payments.value; j++)
            pow = pow * (1 + i);
        form.payment.value = Math.round((form.principal.value * pow * i) / (pow - 1))
    }
        function clearForm(objName) {
			var obj=document.getElementById(objName)
			for (i=0;i<obj.elements.length;i++)
			if (obj.elements[i].type == "text" )
					obj.elements[i].value=""
		 return; 
    }
	function funcLoad(objName)
	{
		var obj=document.getElementById(objName)
		computeForm(obj)
	}