dt_ann_calculate = function()

{

	var investment = document.getElementById("ann_investment").value;

	if ( investment.length == 0 )

	{

		 alert("Please enter the amount of your investment");

		 return;

	}

	investment = fixNumber(investment);

	investment = parseFloat(investment);

	if ( isNaN(investment) )

	{

		 alert("Please enter the amount of your investment as a number");

		 return;

	}

	if ( investment < 0 )

	{

		 alert("Please enter an investment amount >= 0");

		 return;

	}

	



	var deposit = document.getElementById("ann_deposit").value;

	if ( deposit.length == 0 )

	{

		 alert("Please enter the amount of your additional monthly deposits");

		 return;

	}

	deposit  = fixNumber(deposit);

	

	// Monthly Deposit

	deposit = (deposit*12);

	

	deposit  = parseFloat(deposit);

	if ( isNaN(deposit ) )

	{

		 alert("Please enter your additional monthly deposits as a number");

		 return;

	}

	if ( deposit < 0 )

	{

		 alert("Please enter an additional deposit amount >= 0");

		 return;

	}





	var rate = document.getElementById("ann_rate").value;

	if ( rate.length == 0 )

	{

		 alert("Please select 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 < -100 )

	{

		alert("Please enter a rate of interest >= -100" );

	}





	var years = document.getElementById("ann_years").value;

	if ( years.length == 0 )

	{

		 alert("Please enter the # of years you will invest your money for");

		 return;

	}

	years = fixNumber(years);

	years= parseFloat(years);

	if ( isNaN(years) )

	{

		 alert("Please enter the # of years as a number");

		 return;

	}

	if ( years <= 0 )

	{

		 alert("Please enter a number of years > 0");

		 return;

	}



	var r = 1 + (rate / 100);

	var initResult = investment * Math.pow(r, years); 

	var depResult;

	if ( rate == 0 )

	{

		depResult = deposit * years;

	}

	else depResult = deposit * ( 1 - Math.pow(r, years) ) / ( 1 - r ); 



	var result = initResult + depResult;

	

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



	//var results = "After " + years + " years at " + rate + "% interest, and adding an additional " + formatDollars(deposit/12) + " per month, your original investment of " + formatDollars(investment) + " will be worth about <b>" + formatDollars(result) + "</b>.";

	var results = "you will earn <b>" + formatDollars(result) + "</b> after " + years + " years.";

	x.innerHTML = results;

	x.style.display = "block";

}



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('title', 'dt-calc-style');

	s.setAttribute('rel','stylesheet');

	s.setAttribute('href',fileName);

	th.appendChild(s);

}

dt_amount_calculate = function()

{

	var investment = 0;

	var totalDeposit = document.getElementById("total_deposit").value;

	if ( totalDeposit.length == 0 )

	{

		 alert("Please enter the amount of your Investment Goal");

		 return;

	}

	totalDeposit  = fixNumber(totalDeposit);

	

	// Monthly Deposit

	

	

	totalDeposit  = parseFloat(totalDeposit);

	if ( isNaN(totalDeposit ) )

	{

		 alert("Please enter your Investment Goal as a number");

		 return;

	}

	if ( totalDeposit < 0 )

	{

		 alert("Please enter your Investment Goal amount >= 0");

		 return;

	}





	var rate = document.getElementById("ann_rate_mo").value;

	if ( rate.length == 0 )

	{

		 alert("Please select 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 < -100 )

	{

		alert("Please enter a rate of interest >= -100" );

	}





	var years = document.getElementById("ann_years_mo").value;

	if ( years.length == 0 )

	{

		 alert("Please enter the # of years you will invest your money for");

		 return;

	}

	years = fixNumber(years);

	years= parseFloat(years);

	if ( isNaN(years) )

	{

		 alert("Please enter the # of years as a number");

		 return;

	}

	if ( years <= 0 )

	{

		 alert("Please enter a number of years > 0");

		 return;

	}



	var r = 1 + (rate / 100);

	

	var depResult;

	deposit = totalDeposit * (1 - r) / ( 1 - Math.pow(r, years) );

	var result = deposit;

	

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



	//var results = "After " + years + " years at " + rate + "% interest, and adding an additional " + formatDollars(deposit/12) + " per month, your original investment of " + formatDollars(investment) + " will be worth about <b>" + formatDollars(result) + "</b>.";

	var results = "you will need to contribute  <b>" + formatDollars(result/12) + "</b> monthly to reach this goal";

	x.innerHTML = results;

	x.style.display = "block";

}





//addJavascript('http://www.dollartimes.com/script/calcutil.js');

//addStylesheet('http://www.dollartimes.com/calculators/on-your-site/calc-css.php');