function showpay() {
	 if ((isNaN(document.calc.loan.value) || document.calc.loan.value.length == 0) || (isNaN(document.calc.months.value) || document.calc.months.value.length == 0) || (isNaN(document.calc.rate.value) || document.calc.rate.value.length == 0)) { 
		 alert("Payment Calculator:\n\n - Incomplete Data");
	} else {
		var princ = document.calc.loan.value;
		var term  = document.calc.months.value;
		var intr   = document.calc.rate.value / 1200;
		document.calc.pay.value = Math.round(princ * intr / (1 - (Math.pow(1/(1 + intr), term))));
	}

// payment = principle * monthly interest/(1 - (1/(1+MonthlyInterest)*Months))

}