//this function use to display cat product using on chnage 
function check_numeric_value(getValue) {

	getValue = document.getElementById(getValue);
	if(numValue(getValue)== false) return false;

}

function check_simple_interest() {

	starting_principal = document.getElementById("starting_principal");
	if(blankValidation(starting_principal,"Starting Principal value cannot be blank.")== false) return false;

	years = document.getElementById("years");
	if(blankValidation(years,"Year value cannot be blank.")== false) return false;

	annual_interest_rate = document.getElementById("annual_interest_rate");
	if(blankValidation(annual_interest_rate, "Annual Interest Rate value cannot be blank.")== false) return false;

}

function doCalc()
{
	zeroBlanks(document.mainform);
	var p = numval(document.mainform.p.value);
	var r = numval(document.mainform.r.value)/100;
	var y = numval(document.mainform.y.value);

	document.mainform.payment.value = formatNumber(mortgagePayment(p,r/12,y*12),2);
}