function checkForNumber(e) {
	var key = window.event ? e.keyCode : e.which;
	var keychar = String.fromCharCode(key);
	reg = /[a-zA-Z]/;
	return !reg.test(keychar);
}

function roundIt(fltNumber, intRound) {
   	if (intRound > 0) {
      	if ((fltNumber.toString().length - fltNumber.toString().lastIndexOf('.')) > (intRound + 1)) {
      		var fltRounder = Math.pow(10, intRound);
      		return Math.round(fltNumber * fltRounder) / fltRounder;
      	} else {
      		return fltNumber;
      	}
   	} else {
		return Math.round(fltNumber);
  	}
}

function calcMortgage() {
	frm = document.forms['mortgageForm'];

	// calculate monthly payemnt
	amt = eval(frm.mortgage.value);
	yrs = eval(frm.terms.value);
	rte = eval(frm.intrest.value)/1200;
	pmt = (rte+(rte/(Math.pow((1+rte),(yrs))-1)))*amt;
	pmt = pmt*100;pmt=Math.round(pmt);pmt=pmt/100;

	// monthly payment
	frm.payment.value = roundIt(pmt, 2);
}