function tpopup(s)
{
	msg=window.open(s, "rblPopup", "scrollbars=no,status=no,toolbar=no,directories=no,menubar=no,location=no,resizable=yes,width=800,height=450");
}


function disable(){
document.form1.payment.readOnly=true;
document.form1.loanAmount.readOnly=true;


document.form1.intm1.readOnly=true;
document.form1.intm05.readOnly=true;
document.form1.intint.readOnly=true;
document.form1.intp05.readOnly=true;
document.form1.intp1.readOnly=true;
document.form1.e6.readOnly=true;

	



document.form1.a1.readOnly=true;
document.form1.a2.readOnly=true;
document.form1.a3.readOnly=true;
document.form1.a4.readOnly=true;
document.form1.a5.readOnly=true;
document.form1.a6.readOnly=true;

document.form1.b1.readOnly=true;
document.form1.b2.readOnly=true;
document.form1.b3.readOnly=true;
document.form1.b4.readOnly=true;
document.form1.b5.readOnly=true;
document.form1.b6.readOnly=true;

document.form1.c1.readOnly=true;
document.form1.c2.readOnly=true;
document.form1.c3.readOnly=true;
document.form1.c4.readOnly=true;
document.form1.c5.readOnly=true;
document.form1.c6.readOnly=true;

document.form1.d1.readOnly=true;
document.form1.d2.readOnly=true;
document.form1.d3.readOnly=true;
document.form1.d4.readOnly=true;
document.form1.d5.readOnly=true;
document.form1.d6.readOnly=true;

document.form1.e1.readOnly=true;
document.form1.e2.readOnly=true;
document.form1.e3.readOnly=true;
document.form1.e4.readOnly=true;
document.form1.e5.readOnly=true;
document.form1.e6.readOnly=true;

}


function payment(a,n,p){
	/* Calculates the monthly payment from annual percentage
		   rate, term of loan in months and loan amount. **/
		var acc=0;
		var base = 1 + p/1200;
		for (i=1;i<=n;i++) 
			{ acc += Math.pow(base,-i); }
		return a/acc;

	/*
	x=d/12;
	y=Math.pow((1+(x)),(e*12));
	
	/* total= ((d/12)+((d/12)/(((1+(d/12))^(e*12))-1)))*c; 
	total= ((x)+((x)/((y)-1)))*c;
	return total;
	*/
}
	

function calculate(what) {
	var totalPrice=parseFloat(what.totalPrice.value).toFixed(2);;
	var downPayment=parseFloat(what.downPayment.value).toFixed(2);;
	var loanTerm=parseFloat(what.loanTerm.value);
    var loanAmount=totalPrice-downPayment;
    what.loanAmount.value = loanAmount.toFixed(2);;
	
	var interest=parseFloat(what.interest.value);
	e=parseFloat(what.loanTerm.value);
	
	/*monthlyPayment= ((d/12)+((d/12)/((1+(d/12))-1)))*loanAmount; */
	
	
	/*monthlyPayment=  (((d/12)+((d/12) /(((1+(d/12))^(e*12))-1)))*loanAmount); */
	
	
	/*total=((d+(d/((1+d)-1))) * e);
	total=  (((d/12)+((d/12)/(((1+(d/12))^(e*12))-1)))*c);*/
	/*total= ((d/12)+((d/12)/(((1+(d/12))^(e*12))-1)))*c; */
	
	        
			
			
	what.payment.value=payment(loanAmount,loanTerm,interest).toFixed(2);

	
	g=(parseFloat(interest)-1);
	what.intm1.value=(parseFloat(interest)-1).toFixed(2)+"%";
	
	h=(parseFloat(interest)-0.5);
	what.intm05.value=(parseFloat(interest)-0.5).toFixed(2)+"%";
	
	l=interest;
	what.intint.value=(parseFloat(interest).toFixed(2))+"%";
	
	j=(parseFloat(interest)+0.5);
	what.intp05.value=(parseFloat(interest)+0.5).toFixed(2)+"%";
	
	k=(parseFloat(interest)+1);
	what.intp1.value=(parseFloat(interest)+1).toFixed(2)+"%";
	

	what.a1.value="$"+payment(loanAmount,12,g).toFixed(2);
	what.b1.value="$"+payment(loanAmount,12,h).toFixed(2);
	what.c1.value="$"+payment(loanAmount,12,l).toFixed(2);
	what.d1.value="$"+payment(loanAmount,12,j).toFixed(2);
	what.e1.value="$"+payment(loanAmount,12,k).toFixed(2);
	
	
	
	what.a2.value="$"+payment(loanAmount,24,g).toFixed(2);
	what.b2.value="$"+payment(loanAmount,24,h).toFixed(2);
	what.c2.value="$"+payment(loanAmount,24,l).toFixed(2);
	what.d2.value="$"+payment(loanAmount,24,j).toFixed(2);
	what.e2.value="$"+payment(loanAmount,24,k).toFixed(2);
	
	
	
	what.a3.value="$"+payment(loanAmount,36,g).toFixed(2);
	what.b3.value="$"+payment(loanAmount,36,h).toFixed(2);
	what.c3.value="$"+payment(loanAmount,36,l).toFixed(2);
	what.d3.value="$"+payment(loanAmount,36,j).toFixed(2);
	what.e3.value="$"+payment(loanAmount,36,k).toFixed(2);
	
	what.a4.value="$"+payment(loanAmount,48,g).toFixed(2);
	what.b4.value="$"+payment(loanAmount,48,h).toFixed(2);
	what.c4.value="$"+payment(loanAmount,48,l).toFixed(2);
	what.d4.value="$"+payment(loanAmount,48,j).toFixed(2);
	what.e4.value="$"+payment(loanAmount,48,k).toFixed(2);
	
	what.a5.value="$"+payment(loanAmount,60,g).toFixed(2);
	what.b5.value="$"+payment(loanAmount,60,h).toFixed(2);
	what.c5.value="$"+payment(loanAmount,60,l).toFixed(2);
	what.d5.value="$"+payment(loanAmount,60,j).toFixed(2);
	what.e5.value="$"+payment(loanAmount,60,k).toFixed(2);
	
	
	what.a6.value="$"+payment(loanAmount,72,g).toFixed(2);
	what.b6.value="$"+payment(loanAmount,72,h).toFixed(2);
	what.c6.value="$"+payment(loanAmount,72,l).toFixed(2);
	what.d6.value="$"+payment(loanAmount,72,j).toFixed(2);
	what.e6.value="$"+payment(loanAmount,72,k).toFixed(2);
	
}