addJavascript = function(fileName) {
	var th = document.getElementsByTagName('head')[0];
	var s = document.createElement('script');
	s.setAttribute('type','text/javascript');
	s.setAttribute('src',fileName);
	th.appendChild(s);
}
addStylesheet = function(fileName) {
	var th = document.getElementsByTagName('head')[0];
	var s = document.createElement('link');
	s.setAttribute('type','text/css');
	s.setAttribute('rel','stylesheet');
	s.setAttribute('href',fileName);
	th.appendChild(s);
}

mtgpay_calculate = function()
{
	var price = document.getElementById("mtgpay_dt_purchaseprice").value;
	if ( price.length == 0 )
	{
		alert("Please enter the purchase price");
		return;
	}
	price = fixNumber(price);
	price = parseFloat(price);
	if ( isNaN(price) )
	{
		alert("Please enter the  purchase price as a number");
		return;
	}
	if ( price < 0 )
	{
		alert("Please enter a purchase price >= 0");
		return;
	}
	
	var rate = document.getElementById("mtgpay_dt_rate").value;
	if ( rate.length == 0 )
	{
		alert("Please enter an interest rate");
		return;
	}
	rate = fixNumber(rate);
	rate = parseFloat(rate);
	if ( isNaN(rate) )
	{
		alert("Please enter the interest rate as a number");
		return;
	}
	if ( rate <= 0 || rate >= 20 )
	{
		alert("Please enter a interest rate greater than 0 and less than 20");
		return;
	}

	var years = parseInt( document.getElementById("mtgpay_dt_duration").value);

	var downpayment = document.getElementById("mtgpay_dt_down").value;
	if ( downpayment.length == 0 )
	{
		alert("Please enter a down payment");
		return;
	}
	downpayment = fixNumber(downpayment);
	downpayment = parseFloat(downpayment);
	if ( isNaN(downpayment) )
	{
		alert("Please enter the down payment as a number");
		return;
	}
	if ( downpayment < 0 )
	{
		alert("Please enter a down payment >= 0");
		return;
	}

	var mrate = rate / 1200;

	var loanamount = price - downpayment;
	var payment;
	if ( years == -1 )
	{
		payment = mrate * loanamount;
	}
	else
	{
		var factor = Math.pow(1 + mrate, years * 12 );
		payment = loanamount * ( mrate / (1 - 1/factor) );
	}

	var x = document.getElementById("mtgpay_dt_results");

	var results = "The amount of your loan will be <b>" + formatDollars(loanamount) + "</b>.";

	results += "<br>Your monthly payment will be <b>" + formatDollars(payment) + "</b>.";
	
	if ( years == -1 )
		results += "<p>";

	x.innerHTML = results;
	x.style.display = "block";
}

// Run Script
addJavascript('http://www.dollartimes.com/script/calcutil.js');
// addStylesheet('http://www.dollartimes.com/styles/dt-calc-on-your-site-v2.css');

var out='\n\
<div id="mtgpay_dt_calculator" class="dt_calculator">\n\
	<h2>Mortgage Payment Calculator</h2>\n\
	<p class="small">Provided by DollarTimes.com</p>\n\
	\n\
	<p class="instructions">This will calculate your approximate monthly mortgage payment based on the purchase price and your loan details. This calculator is for fixed-rate mortgages.</p>\n\
	\n\
	<div class="a">Purchase Price</div>\n\
	<div class="b">$</div>\n\
	<div class="c"><input id="mtgpay_dt_purchaseprice" type="text"></div>\n\
	<div class="clear"></div>\n\
	<div class="a">Down Payment</div>\n\
	<div class="b">$</div>\n\
	<div class="c"><input id="mtgpay_dt_down" type="text"></div>\n\
	<div class="clear"></div>\n\
	<div class="a">Interest Rate</div>\n\
	<div class="b">%</div>\n\
	<div class="c"><input id="mtgpay_dt_rate" value="6.25" type="text"></div>\n\
	<div class="clear"></div>\n\
	<div class="a">Term of the Loan</div>\n\
	<div class="b">&nbsp;</div>\n\
	<div class="c"><select id="mtgpay_dt_duration"><option value="5">5 years</option><option value="10">10 years</option><option value="15">15 years</option><option value="20">20 years</option><option value="25">25 years</option><option selected="selected" value="30">30 years</option><option value="40">40 years</option><option value="-1">Interest Only</option></select></div>\n\
	<div class="clear"></div>\n\
	<div class="d"><button onclick="mtgpay_calculate()">Calculate</button></div>\n\
	<div id="mtgpay_dt_results" class="dt_results">\n\
</div>\n\
';

var url = 'mortgage-payment.htm';

var baseUrl = 'http://www.dollartimes.com/calculators/';
var scriptUrl = 'on-your-site/' + url.split('.')[0] + '.js';

var scriptEls = document.getElementsByTagName('script')
var scriptEl=false;
for(i=0; i<scriptEls.length; i++)
{
	var t = scriptEls[i];
	var src = (t.getAttribute('src'));
	if(src == (baseUrl + scriptUrl))
	{
		scriptEl = t;
		break;
	}
}