function checkAmount(fname,amt,label) {
	var validChars = "0123456789.";
	var theValue = document[fname][amt].value;
	var theLength = theValue.length;
	for(i = 0; i < theLength; i++) {
		char2chk = theValue.substr(i,1);
		if (validChars.indexOf(char2chk) == "-1") {
			alert(label + " must contain only numbers and, if applicable, a decimal point");
			document[fname][amt].focus();
			return false;
		}
	}
}
function disallowInput() {
	alert("This field is calculated automatically");
	document.form.LoanAmount.focus();
}
function calcPayment() {
	var Principle = document.form.LoanAmount.value;
	if(!(Principle > 0)) {
		alert("Please enter a valid loan amount");
	}
	var Rate = document.form.LoanRate.value;
	if(!(Rate > 0)) {
		alert("Please enter a valid interest rate");
	}
	var TermIndex = document.form.LoanTerm.selectedIndex;
	var Term = document.form.LoanTerm.options[TermIndex].value;
	if(!(Term > 0)) {
		alert("Please select a valid loan term");
	}
	var Payment = Math.round((Principle*((Rate/(1200))/(1-(Math.pow(1+(Rate/(1200)),((Term*12)*-1))))))*100)/100;
	document.form.LoanPayment.value=Payment;
}
function calcAmt(frm) {
	princ = frm.pr.value;
	ratepc = frm.rt.value;
	years = frm.yr.value;
	frm.amt.value = Math.round(princ*(Math.pow((1+ratepc/100),years))*100)/100;
	frm.intr.value = Math.round((princ*(Math.pow((1+ratepc/100),years))-princ)*100)/100
}