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

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

	var ratio = waist / hip;

	var gender = document.getElementById("gender").value;
	


	var risk;
	if ( gender == "male" )
	{
		if ( ratio <= .95 )
			risk = "LOW";
		else if ( ratio <= 1.0 )
			risk = "MEDIUM";
		else
			risk = "HIGH";
	}

	if ( gender == "female" )
	{
		if ( ratio <= .80 )
			risk = "LOW";
		else if ( ratio <= .85 )
			risk = "MEDIUM";
		else
			risk = "HIGH";
	}

	var x = document.getElementById("results");
	var results = "Your waste to hip ratio is <span style='color:red'>" + ratio.toFixed(2) + "</span>.  Your risk level for heart disease is <span style='color:red'>" + risk + "</span>";
	results += "<p>The ideal ratio is considered to be .90 for men and .70 for women.";

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

function logo(x)
{
	return Math.log(x) / Math.log(10);
}