// JavaScript Document

		var ns4 = (document.layers)? true:false
		var ie4 = (document.all)? true:false
		function init() {
				document.onkeydown = pressKey
				if (ns4) document.captureEvents(Event.KEYDOWN)
		}

		function pressKey(e) {
				if (ns4) {var nKey=e.which; var ieKey=0}
				if (ie4) {var ieKey=event.keyCode; var nKey=0}
				if (nKey==13 || ieKey==13) {
						document.Calc.btCalc.click();
				}
		}

		function checkNum(obj)  {
			var str = obj.value;
			var re = /^\d{0,5}\.?\d{0,3}$/;
			//var re2 = /[0-9]/g;
			if (! re.test(str)) {
				alert('Invalid value. Please enter a number.');
				obj.select();
				return false;
			}
			else
				return true;
		}

		function calc() {
			if (checkNum(document.Calc.txtTripMiles) && checkNum(document.Calc.txtTripDays)
				&& checkNum(document.Calc.txtMPG) && checkNum(document.Calc.txtFuelCost)
				&& checkNum(document.Calc.txtMisc) && checkNum(document.Calc.txtMaint))
			{
				var A = parseFloat(document.Calc.txtTripMiles.value);
				var B = parseFloat(document.Calc.txtTripDays.value);
				var C = parseFloat(document.Calc.txtMPG.value);
				var D = parseFloat(document.Calc.txtFuelCost.value);
				var E = parseFloat(document.Calc.txtMisc.value);
				var F = parseFloat(document.Calc.txtMaint.value);
				var tripCost = 0;

				if (A <= 0) {
					alert('Please enter the total esitmated trip miles.');
					document.Calc.txtTripMiles.select();
					return false;
				}

				if (C <= 0) {
					alert('Please enter the average miles per gallon for your vehicle.');
					document.Calc.txtMPG.select();
					return false;
				}

				tripCost = Math.round((((D / C) + F) * A * B + E) * 100) / 100;

				tripCost = tripCost.toString();

				if (tripCost.length - (tripCost.indexOf('.') + 1) < 2)
					tripCost += '0';

				document.Calc.txtTripCost.value = tripCost;
			}
		}