var initExerciseCalorieCounter = function () 
	{
		var calculate = document.getElementById('calculate');
		var result = document.getElementById('result');
		var pounds = document.getElementById('pounds');

		var aerobics = document.getElementById('aerobics');
		var cleaning = document.getElementById('cleaning');
		var cycling = document.getElementById('cycling');
		var dancing = document.getElementById('dancing');
		var football = document.getElementById('football');
		var gardening = document.getElementById('gardening');
		var jogging = document.getElementById('jogging');
		var karate = document.getElementById('karate');
		var rowing = document.getElementById('rowing');
		var running = document.getElementById('running');
		var swimming = document.getElementById('swimming');
		var walking = document.getElementById('walking');
		var weights = document.getElementById('weights');
		var tennis = document.getElementById('tennis');

		top.YAHOO.util.Event.addListener(calculate, 'click', getCaloriesBurned);

		YAHOO.util.Event.addListener(pounds, 'focus', function () { if (this.value == 'Pounds') this.value = ''; });
		YAHOO.util.Event.addListener(pounds, 'blur', function () { if (this.value == '') this.value = 'Pounds'; });


		function getNumberForValue(value)
		{
			var val = parseInt(value);
			if (isNaN(val))
			{
				return 0;
			}
			return val;
		}

		function getCaloriesBurned(evnt)
		{
			YAHOO.util.Event.stopEvent(evnt);
			var sum = 0;
			var caloriesPerHr = 0;
			var caloriesBurned = 0;
			var activities = new Array();
			var kgs = getNumberForValue(pounds.value) * 0.4536;

			activities.push({ minutes: getNumberForValue(aerobics.value), intensity: 7 });
			activities.push({ minutes: getNumberForValue(cleaning.value), intensity: 2.7 });
			activities.push({ minutes: getNumberForValue(cycling.value), intensity: 9 });
			activities.push({ minutes: getNumberForValue(dancing.value), intensity: 5 });
			activities.push({ minutes: getNumberForValue(football.value), intensity: 8 });
			activities.push({ minutes: getNumberForValue(gardening.value), intensity: 3 });
			activities.push({ minutes: getNumberForValue(jogging.value), intensity: 8.5 });
			activities.push({ minutes: getNumberForValue(karate.value), intensity: 10 });
			activities.push({ minutes: getNumberForValue(rowing.value), intensity: 7.2 });
			activities.push({ minutes: getNumberForValue(running.value), intensity: 10.5 });
			activities.push({ minutes: getNumberForValue(swimming.value), intensity: 8 });
			activities.push({ minutes: getNumberForValue(walking.value), intensity: 3.5 });
			activities.push({ minutes: getNumberForValue(weights.value), intensity: 6 });
			activities.push({ minutes: getNumberForValue(tennis.value), intensity: 7 });

			for (var i = 0; i < activities.length; i++)
			{
				var activity = activities[i];
				caloriesPerHr = activity.intensity * kgs;
				caloriesBurned = (caloriesPerHr * activity.minutes) / 60;
				sum += caloriesBurned;
			}

			if (!isNaN(sum))
			{
				result.value = sum.toFixed(2);
			}

			return false;
		}

	};
	
	// Register event handlers
	YAHOO.util.Event.addListener(window, 'load', initExerciseCalorieCounter);