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);
}

mtgcomp_calculate = function()
{
	var price = document.getElementById("mtgcomp_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 downpayment = document.getElementById("mtgcomp_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 rate15 = document.getElementById("mtgcomp_rate15").value;
	if ( rate15.length == 0 )
	{
		alert("Please enter the 15-year interest rate");
		return;
	}
	rate15 = fixNumber(rate15);
	rate15 = parseFloat(rate15);
	if ( isNaN(rate15) )
	{
		alert("Please enter the 15-year interest rate as a number");
		return;
	}
	if ( rate15 <= 0 || rate15 >= 30 )
	{
		alert("Please enter a 15-year interest rate greater than 0 and less than 30");
		return;
	}


	var rate30  = document.getElementById("mtgcomp_rate30").value;
	if ( rate30.length == 0 )
	{
		alert("Please enter the 30-year interest rate");
		return;
	}
	rate30 = fixNumber(rate30);
	rate30 = parseFloat(rate30);
	if ( isNaN(rate30) )
	{
		alert("Please enter the 30-year interest rate as a number");
		return;
	}
	if ( rate30 <= 0 || rate30 >= 30 )
	{
		alert("Please enter a 30-year interest rate greater than 0 and less than 30");
		return;
	}

	var loanamount = price - downpayment;

	var payment15 = calcPayment(loanamount, rate15, 15);
	var payment30 = calcPayment(loanamount, rate30, 30);


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

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

	results += "<p>With a 15-year mortgage, your monthly payment will be <b>" + formatDollars(payment15) + "</b>.";
	results += "<p>With a 30-year mortgage, your monthly payment will be <b>" + formatDollars(payment30) + "</b>.";
	results += "<p>The advantage of a 15-year mortgage is that you own your house sooner, and you accumulate principal more quickly.";


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

// RUN SCRIPT (*do not check for link)

addJavascript('calcutil.js');
addStylesheet('calc.css');
var out = '\
<div id="mtgcomp_dt_calculator" class="dt_calculator">\n\
	<p class="instructions">This calculator will offer a comparison of 15 and 30 year mortgages.</p>\n\
	<div class="a">Purchase Price</div>\n\
	<div class="b">$</div>\n\
	<div class="c"><input id="mtgcomp_purchaseprice" type="text" /></div>\n\
	<div class="a">Down Payment</div>\n\
	<div class="b">$</div>\n\
	<div class="c"><input id="mtgcomp_down" type="text" /></div>\n\
	<div class="a">15 Year Interest Rate</div>\n\
	<div class="b">%</div>\n\
	<div class="c"><input id="mtgcomp_rate15" type="text" /></div>\n\
	<div class="a">30 Year Interest Rate</div>\n\
	<div class="b">%</div>\n\
	<div class="c"><input id="mtgcomp_rate30" type="text" /></div>\n\
	<div class="clear"></div>\n\
	<div class="d"><button onclick="mtgcomp_calculate()">Calculate</button></div>\n\
	<div id="mtgcomp_dt_results" class="dt_results">&nbsp;</div>\n\
</div>\n\
';
var url = '15-and-30-year-mortgage-comparison.htm'

//var baseUrl = 'http://localhost/';
//var scriptUrl = 'on-your-site/' + url.split('.')[0] + '.js';
var baseUrl = '';
var scriptUrl = 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;
	}
}
if(!scriptEl)
{
	//document.write('\n<p>Failed loading calculator. </p>');
}
else
{
	var par = scriptEl.parentNode;
	var link = par.getElementsByTagName('a')[0];
	var el = document.createElement('div');
	el.innerHTML = out;
	par.appendChild(el);
	
	if(link && link.href==baseUrl + url) {
		link.style.fontSize="80%";
		var calcDiv = document.getElementById('mtgcomp_dt_calculator');
		if(calcDiv)	{
			// Put link on bottom of calculator box
			par.removeChild(link)			
			calcDiv.appendChild(link);	
		}
	}
}