function calcNav(navForm) {
	var URL = document.navForm.calcPage.options[document.navForm.calcPage.selectedIndex].value;
	window.location.href = URL;
}

function validateForm() {
	var form = document.ppmForm;

	if (document.ppmForm.pPrice.value == "")
		{
		alert("Enter Price per Pound.");
		document.ppmForm.pPrice.focus();
		return (false);
		}

	if (isNaN(document.ppmForm.pPrice.value))
		{
		alert("Price per Pound must be a valid number.");
		document.ppmForm.pPrice.focus();
		return (false);
		}

	if (document.ppmForm.bWeight.value == "")
		{
		alert("Enter Basis Weight.");
		document.ppmForm.bWeight.focus();
		return (false);
		}

	if (isNaN(document.ppmForm.bWeight.value))
		{
		alert("Basis Weight must be a valid number.");
		document.ppmForm.bWeight.focus();
		return (false);
		}

	if (document.ppmForm.hArea.value == "")
		{
		alert("Enter Basic Size (Height).");
		document.ppmForm.hArea.focus();
		return (false);
		}

	if (isNaN(document.ppmForm.hArea.value))
		{
		alert("Basic Size (Height) must be a valid number.");
		document.ppmForm.hArea.focus();
		return (false);
		}

	if (document.ppmForm.wArea.value == "")
		{
		alert("Enter Basic Size (Width).");
		document.ppmForm.wArea.focus();
		return (false);
		}

	if (isNaN(document.ppmForm.wArea.value))
		{
		alert("Basic Size (Width) must be a valid number.");
		document.ppmForm.wArea.focus();
		return (false);
		}

	CalculatePPM(form.pPrice.value,form.bWeight.value,form.hArea.value,form.wArea.value);

CalculatePPM2(form.Answer1.value);

	return true;
}

function CalculatePPM(pPrice,bWeight,hArea,wArea) {
	var ppm = pPrice * ((bWeight / (hArea * wArea)) * 2);
	document.ppmForm.Answer1.value = formatNumber(ppm,4);
}

function CalculatePPM2(Answer1) {
	var ppm2 = Answer1 * 144;
	document.ppmForm.Answer2.value = formatNumber(ppm2,4);
}


function formatNumber(val,places) {
	var power = 1;
	if (places> 0) {
		power = Math.pow(10,places);
	}

	var roundedNum = (Math.round(val * power)/power) + "";


	var decpos = roundedNum.indexOf(".");

	if (decpos>= 0) {
		var decDiff = places-(roundedNum.length-(decpos+1));
	} else {
		var decDiff = places;
		if (places> 0) {
			roundedNum += ".";
		}
	}


	for (var x = 0; x < decDiff; x++) {
		roundedNum += "0";
	}
    return roundedNum;
}


function setValues() {
	var form = document.ppmForm;
	var area = form.Area.value;

	if (area == 0) { form.hArea.value = ""; form.wArea.value = ""; }
	if (area == 1) { form.hArea.value = 17; form.wArea.value = 22; }
	if (area == 2) { form.hArea.value = 25; form.wArea.value = 38; }
	if (area == 3) { form.hArea.value = 24; form.wArea.value = 36; }
	if (area == 4) { form.hArea.value = 25.5; form.wArea.value = 30.5; }
	if (area == 5) { form.hArea.value = 22.5; form.wArea.value = 30.5; }
	if (area == 6) { form.hArea.value = 24; form.wArea.value = 36; }
	if (area == 7) { form.hArea.value = 20; form.wArea.value = 26; }
	if (area == 8) { form.hArea.value = 25; form.wArea.value = 38; }
	if (area == 9) { form.hArea.value = 20; form.wArea.value = 26; }
	if (area == 10) { form.hArea.value = 288; form.wArea.value = 1; }
}