// JavaScript Document
/***************************
(c) 2008 www.TUFaT.com
All Rights Reserved. Please
do not re-sell/re-distribute
this software.
***************************/
function CalcHowmuch(form)
{
	var ai = form.ai.value;
	var md = form.md.value;
	var dp = form.dp.value;
	var pt = form.pt.value;
	var hi = form.hi.value;
	var ir = form.ir.value;
	var yr = form.yr.value;
	var StrOut='';
  	var r1 = 28; 
	var r2 = 36; 
	
  	var mi = ai/12; 
	var c1 = mi * r1 / 100;
  	var c2 = (mi * r2 / 100) - md;
  
  	if (c1 < c2)
  	{
		StrOut=StrOut+'<p>';    
		StrOut=StrOut+"<strong>We must use the "+formatNumberDec(r1,2,1)+"% amount of $"+formatNumberDec(c1,2,1)+" for PITI </strong><br/> - This is because this value is lower than the amount ";
		StrOut=StrOut+"($"+formatNumberDec(c2,2,1)+") calculated using the "+formatNumberDec(r2,2,1)+"% monthly debt value. <br/><br/>";
    	piti = c1;
  	}
  	else
  	{
    	StrOut=StrOut+"<p><strong>We must use the "+formatNumberDec(r2,2,1)+"% amount of $"+formatNumberDec(c2,2,1)+" for PITI </strong><br/> - This is because this value is lower than the amount ";
    	StrOut=StrOut+"($"+formatNumberDec(c1,2,1)+") calculated using the "+formatNumberDec(r1,2,1)+"% income only value <br/>";
    	StrOut=StrOut+"To use the lower "+formatNumberDec(r1,2,1)+"% limit, try to keep your monthly debt payments below $ "+formatNumberDec((mi * (r2 - r1)/100),2,1)+" (reduce them by $ "+formatNumberDec((md - mi * (r2 - r1)/100),2,1)+") <br/><br/>";
    	piti = c2;
  	}
	j = ir/1200; 
	amv = (1 - Math.pow((1 + j),((-1)*yr*12)))/j;
 	StrOut=StrOut+"<strong>Your interest rate of "+formatNumberDec(ir,2,1)+"% over "+yr+" years means every dollar you pay each month buys you $ "+formatNumberDec(amv,2,1)+" of loan</strong><br/><br/>";
	piti_ov = eval(hi) + eval(pt); 
 	StrOut=StrOut+"<strong>You stated Tax and Insurance would total "+formatNumberDec(piti_ov,2,1)+"% the home value</strong><br/>";
	StrOut=StrOut+" <strong>And with $ "+formatNumberDec(dp,2,1)+" to cover your down payment</strong></p>";
	house = 1000; 
	pmt = piti; 
	loan = 1000;
	for (i=0; i<20; i++) 
	{
		ti = piti_ov/1200 * house;
		loan = (piti - ti) * amv;
		house = eval(loan) + eval(dp);
	}
 	dpp = dp/house*100; 
	ltv = (house-dp)/house*100;
	
	StrOut=StrOut+'<table border="0" valign="top" width=100%><tr>';
	StrOut=StrOut+'<td width=50%>House value:</td>';
	StrOut=StrOut+'<td bgcolor="#FFFFFF"><b>';
	StrOut=StrOut+ '$'+ formatNumberDec(house,2,1); 
	StrOut=StrOut+'</b></td></tr><tr>';
	StrOut=StrOut+'<td width=50%>Loan value:</td>';
	StrOut=StrOut+'<td bgcolor="#FFFFFF"><b>';
	StrOut=StrOut+" $"+formatNumberDec(loan,2,1);
	StrOut=StrOut+'</b></td></tr><tr>';
	StrOut=StrOut+'<td width="50%" >';
	StrOut=StrOut+'Monthly Principal+Interest:</td>';

	StrOut=StrOut+'<td bgcolor="#FFFFFF"><b>';
	StrOut=StrOut+ "$"+formatNumberDec((loan/amv),2,1);
	StrOut=StrOut+'</b></td></tr><tr>';
	StrOut=StrOut+'<td width="50%" >';
	StrOut=StrOut+'Monthly Prop Tax+Insurance:</td>';

	StrOut=StrOut+'<td bgcolor="#FFFFFF"><b>';
	StrOut=StrOut+" $"+formatNumberDec((house*piti_ov/1200),2,1);
	StrOut=StrOut+'</b></td></tr><tr>';
	StrOut=StrOut+'<td  width=50%>Down Payment:</td>';

	StrOut=StrOut+'<td bgcolor="#FFFFFF"><b>';
	StrOut=StrOut+ formatNumberDec(dpp,2,1)+"%";
	StrOut=StrOut+'</b></td></tr><tr>';
	StrOut=StrOut+'<td  width=50%>Loan To Value(LTV):</td>';

	StrOut=StrOut+'<td bgcolor="#FFFFFF"><b>';
	StrOut=StrOut+ formatNumberDec(ltv,2,1)+"%"; 
	StrOut=StrOut+'</b></td></tr></table>';
	if (ltv>80)
 	{
	   StrOut=StrOut+"<br/><strong>OOPS! Your down payment is less than 20%! You pay PMI</span><br />";
	   house = 1000; 
	   pmt = piti; 
	   loan = 1000; 
	   var ty='';
		if (ty == 'Conv')
		{
			pmi = .32;
			if (ltv>=85) { pmi = .52; }
			if (ltv>=90) { pmi = .78; }
			if (ltv>=95) { pmi = .90; }
		} else { 
			pmi = .5; 
		}
		piti_ov += pmi;
		StrOut=StrOut+"That's an extra "+pmi+"% of your loan each year";
		for (i=0; i<20; i++) 
		{
			ti = piti_ov/1200 * house;
			loan = (piti - ti) * amv;
			house = eval(loan) + eval(dp);
		}
		dpp = dp/house*100;
	
		StrOut=StrOut+'<table border="0" valign="top" width="100%"><tr>';
		StrOut=StrOut+'<td  width=50%>House value:</td>';
		StrOut=StrOut+'<td bgcolor="#FFFFFF"><b>';
		StrOut=StrOut+" $"+formatNumberDec(house,2,1);
		StrOut=StrOut+'</b></td></tr><tr>';
		StrOut=StrOut+'<td  width=50%>Loan value:</td>';
		StrOut=StrOut+'<td bgcolor="#FFFFFF"><b>';
		StrOut=StrOut+" $"+formatNumberDec(loan,2,1);
		StrOut=StrOut+'</b></td></tr><tr>';
		StrOut=StrOut+'<td width="50%" >';
		StrOut=StrOut+'Monthly Principal+Interest:</td>';
		StrOut=StrOut+'<td bgcolor="#FFFFFF"><b>';
		StrOut=StrOut+" $"+formatNumberDec((loan/amv),2,1); 
		StrOut=StrOut+'</b></td></tr><tr>';
		StrOut=StrOut+'<td  width=50%>Monthly Prop Tax+Insurance:</td>';
		StrOut=StrOut+'<td bgcolor="#FFFFFF"><b>';
		StrOut=StrOut+" $"+formatNumberDec((house*(piti_ov-0.5)/1200),2,1);
		StrOut=StrOut+'</b></td></tr><tr>';
		StrOut=StrOut+'<td  width=50%>Down Payment:</td>';
		StrOut=StrOut+'<td bgcolor="#FFFFFF"><b>';
		StrOut=StrOut+ formatNumberDec(dpp,2,1)+"%";
		StrOut=StrOut+'</b></td></tr><tr>';
		StrOut=StrOut+'<td  width=50%>Monthly PMI:</td>';
		StrOut=StrOut+'<td bgcolor="#FFFFFF"><b>';
		StrOut=StrOut+" $"+formatNumberDec((house*pmi/1200),2,1);    
		StrOut=StrOut+'</b></td></tr>';
		StrOut=StrOut+'</table>';
	}

	document.getElementById("results").innerHTML=StrOut;
	document.getElementById("results").style.display='block';
}