function calculate()
{  
	var savings = document.getElementById("savings").value;
	if ( savings.length == 0 )
	{
		 alert("Please enter your current savings");
		 return;
	}
	savings = fixNumber(savings);
	savings = parseFloat(savings);
	if ( isNaN(savings) )
	{
		 alert("Please enter your current savings as a number");
		 return;
	}

	if ( savings >= 1000000 )
	{
		var x = document.getElementById("results");
		x.innerHTML = "You are already a millionaire.  Congratulations!";
		x.style.display = "block";
		return;
	}

	var deposits = document.getElementById("deposits").value;
	if ( deposits.length == 0 )
	{
		 alert("Please enter your monthly deposits");
		 return;
	}
	deposits = fixNumber(deposits);
	deposits = parseFloat(deposits);
	if ( isNaN(deposits) )
	{
		 alert("Please enter your monthly deposits as a number");
		 return;
	}
	if ( deposits < 0 )
	{
		alert("Please enter monthly deposits >= 0");
	}	

	var rate = document.getElementById("rate").value;
	if ( rate.length == 0 )
	{
		 alert("Please enter your rate of return");
		 return;
	}
	rate = fixNumber(rate);
	rate = parseFloat(rate);
	if ( isNaN(rate) )
	{
		 alert("Please enter your rate of a return as a number");
		 return;
	}
	if ( rate < 0 )
	{
		alert("Please enter an interest rate >= 0");
	}


	var age = document.getElementById("age").value;
	if ( age.length == 0 )
	{
		 alert("Please enter your age");
		 return;
	}
	age = fixNumber(age);
	age = parseInt(age);
	if ( isNaN(age) )
	{
		 alert("Please enter your age as a number");
		 return;
	}
	if ( age < 0 )
	{
		alert("Please enter an age >= 0");
	}	


	var m;
	var r = 1 + (rate / 100);
	var mr = Math.pow( r, (1/12) );
	var d = savings;

	for ( m=0; m<1200; m++ )
	{
		d = d * mr + deposits;
		if ( d >= 1000000 )
			break;	
	}

	var x = document.getElementById("results");
	var results;
	if ( d < 1000000 )
	{
		results = "Sorry, at this rate you won't be a millionaire in the next hundred years.";
	}
	else
	{
		var y = Math.floor(m / 12);
		results = "At this rate, you will be a millionaire in " + y + " years and " + (m%12) + " months.  You are now " + age + ", so you will be a millionaire by age " + (age + y) + ".";
	}
	x.innerHTML = results;
	x.style.display = "block";
	


	


}