// Simple Mortgage Calculator V2.0
// Copyright 2001-2005 SidePix Inc - Daryl Maksymec
function Calculate(){
var form=document.calc;
c=2;
m=form.mort.value;
r=form.rate.value;
a=form.amor.value;
f=sI(form.freq.selectedIndex);
if((m==null||m.length==0)||(m<10000||m>10000000)){
alert('Amount to Mortgage:\nPlease enter a number between 10000 and 10000000.');return false;}
if((r==null||r.length==0)||(r<1||r>25)){
alert('Interest Rate:\nPlease enter a number between 1.0 and 25.0.');return false;}
if((a==null||a.length==0)||(a<1||a>30)){
alert('Amortization Period:\nPlease enter a number between 1 and 30.');return false;}
var p=cP(c,m,r,a,f);
form.pay.value='$'+rD(p);
form.y01.value='$'+rD(cB(c,m,r,f,p,(12/(12/f))));
form.y02.value='$'+rD(cB(c,m,r,f,p,(24/(12/f))));
form.y03.value='$'+rD(cB(c,m,r,f,p,(36/(12/f))));
form.y05.value='$'+rD(cB(c,m,r,f,p,(60/(12/f))));
form.y10.value='$'+rD(cB(c,m,r,f,p,(120/(12/f))));
return true;
}
function sI(n){
if(n==0)return 12;
if(n==1)return 24;
if(n==2)return 26;
if(n==3)return 52;
}
function rD(n){
if(n > 0){
if (n.toFixed)
return n.toFixed(2);
return Math.round(n*100)/100;
}
else return 0;
}
function cB(c,m,r,f,p,t){
R=Math.pow((1.0+((r/100)/c)),(c/f))-1.0;;
return (m*(Math.pow((1.0+R),(t))))-((p*((Math.pow((1.0+R),(t)))-1.0))/R);
}
function cP(c,m,r,a,f){
a=a*12;
var R=Math.pow((1.0+((r/100)/c)),(c/12))-1.0;
var P=(m*R*(Math.pow((1.0+R),a)))/((Math.pow((1.0+R),a))-1.0);
if(f==12) return P;
if(f==52) return P/4.0;
return P/2.0;
}