/* CALCULATES VALUES DISPLAYED WHEN COMPUTE IS CLICKED. FIRST CHECKS THAT THERE ARE VALUES IN ALL OF THE FIELDS. THE RESULTS ARE SENT TO THE TEXT BOXES - MAXIMUM MORTGAGE AND MONTHLY PAYMENT */

function calcMax(){

if((document.maxcalc.totinc.value == null || document.maxcalc.totinc.value.length == 0)|| (document.maxcalc.totinc.value < 10000 || document.maxcalc.totinc.value > 1000000)){
fixpro('Annual Family Income\n','Please enter a number between 10000 and 1000000.');return;}

if((document.maxcalc.protax.value == null || document.maxcalc.protax.value.length == 0)|| (document.maxcalc.protax.value < 100 || document.maxcalc.protax.value > 50000)){
fixpro('Annual Property Taxes\n','Please enter a number between 100 and 50000.');return;}

/*
if((document.maxcalc.proheat.value == null || document.maxcalc.proheat.value.length == 0)|| (document.maxcalc.proheat.value < 20 || document.maxcalc.proheat.value > 1500)){
fixpro('Monthly Heating Costs/Condo Fees\n','Please enter a number between 20 and 1500.');return;}
*/

if((document.maxcalc.debt.value == null || document.maxcalc.debt.value.length == 0)|| (document.maxcalc.debt.value < 0 || document.maxcalc.debt.value > 5000)){
fixpro('Monthly Payments for Loans/Credit Cards\n','Please enter a number between 0 and 5000.');return;}

/*
if((document.maxcalc.second.value == null || document.maxcalc.second.value.length == 0)|| (document.maxcalc.second.value < 0 || document.maxcalc.second.value > 5000)){
fixpro('Secondary Financing Payment\n','Please enter a number between 0 and 5000.');return;}
*/

if((document.maxcalc.rate.value == null || document.maxcalc.rate.value.length == 0)|| (document.maxcalc.rate.value < 2 || document.maxcalc.rate.value > 15)){
fixpro('Interest Rate\n','Please enter a number between 2 and 15.');return;}


var RATE = document.maxcalc.rate.value/100;
var income = document.maxcalc.totinc.value;
var tax = document.maxcalc.protax.value;

if(document.maxcalc.proheat.value == null || document.maxcalc.proheat.value.length == 0) {
	var heat = 1200;
}
else if (document.maxcalc.included.checked) {
	// Divide the condo fee by two to use 50% of entered value
	// Use $1,200 as an absolute minimum
	var heat = Math.max((document.maxcalc.proheat.value*12/2), 1200);
}
else {
	// Divide the condo fee by two to use 50% of entered value
	// Add on the default $100/month heating cost
	var heat = (document.maxcalc.proheat.value*12/2) + 1200;
}

var debt = document.maxcalc.debt.value*12;
// var second = document.maxcalc.second.value*12;
var second = 0;
var compound = 2/12;
var monTime = 25 * 12;
var yrRate = RATE/2;
var rdefine = Math.pow((1.0 + yrRate),compound)-1.0;
var purchcompound = Math.pow((1.0 + rdefine),monTime);


var maxgdsr =.32;
var maxtdsr =.40;


var GDSPAY = (maxgdsr*income) - tax - heat - second;
var TDSPAY = (maxtdsr*income) - tax - heat - second - debt;

var PAYMENT = (GDSPAY<TDSPAY) ? GDSPAY/12 : TDSPAY/12;
var MORTGAGE = (0 +((PAYMENT*(purchcompound-1.0))/rdefine))/purchcompound;


document.maxcalc.amt.value = '$'+roundPen(MORTGAGE);
document.maxcalc.pay.value = '$'+roundPen(PAYMENT);

showLayer('answer');

return;
}


/* OPENS POP UP WINDOW TO DISPLAY HELP MESSAGES IN NETSCAPE 3.0 AND 4.0 */

/*
function winopen(name)
{
var linkit = "help/"+name;
if(versTest() == true || nineTest()==true){	
maxMo=window.open(linkit,'helpscreen','toolbar=no,location=no,directories=no,status=no,scrollbars=yes,resizable=no,copyhistory=no,width=250,height=180,outerWidth=300,outerHeight=230');
if(navigator.appName.substring(0,8) == "Netscape")
{maxMo.focus();}
}

else{location.href=linkit;}

}
*/

/*
maxtitle = new StringArray(9);
maxtitle['A'] = 'Total Annual Income';
maxtitle['B'] = 'Annual Property Taxes';
maxtitle['C'] = 'Monthly Heating Costs';
maxtitle['D'] = 'Other Monthly Debt Payments';
maxtitle['E'] = 'Mortgage Term';
maxtitle['F'] = 'Interest Rate';
maxtitle['G'] = 'Special Circumstances';
maxtitle['H'] = 'Second Mortgage Payments';
maxtitle['I'] = 'Maintenance Fees';
*/

/*
function makeImg()
{
if(browTest()==true){
Img = new Image();
Img.src = "images/back_on.gif"; 
document.images.Back_button.src=Img.src;
}
else{}
} 

function clearImg()
{
if(browTest()==true){
OrImg= new Image();
OrImg.src="images/back_off.gif";
document.images.Back_button.src=OrImg.src;
}
else{}
}

function loadImg()
{
if(browTest()==true){
Img = new Image();
Img.src = "images/back_on.gif"
}
else{}
}
*/