function validatePrompt(Ctrl,PromptStr) {
	alert (PromptStr)
	if (lftForm.rWeight.value == "") {
		Ctrl.focus();
	}
	if (lftForm.rWidth.value == "") {
		Ctrl.focus();
	}
	if (lftForm.bWeight.value == "") {
		Ctrl.focus();
	}
	if (lftForm.hArea.value == "") {
		Ctrl.focus();
	}
	if (lftForm.wArea.value == "") {
		Ctrl.focus();
	}
	return;
}

function testBlank(objField,FieldName) {
	var strField = new String(objField.value);
	if (objField.value == "") {
		validatePrompt (objField, "\""+FieldName+"\" cannot be blank.")
		return (false);
	} else {
		return (true);
	}
}

function testNumber(objField, FieldName) {
	var numField = objField.value;

	if (isNaN(numField)) {
		validatePrompt (objField, "\""+FieldName+"\" must be a valid number.")
		return (false);
	}

	numField = parseFloat(numField);

	if (numField> 0) {
		return (true);
	} else {
		validatePrompt (objField, "\""+FieldName+"\" must be a number greater than 0.")
		return (false);
	}
}

function testValue(objField, FieldName) {
	if (!testBlank(objField,FieldName)) return false;
	if (!testNumber(objField,FieldName)) return false;
	return true;
}

function validateForm() {
	var form = document.lftForm;
	if (!testValue(form.rWeight,"Roll Weight")) return false;
	if (!testValue(form.rWidth,"Roll Width")) return false;
	if (!testValue(form.bWeight,"Basis Weight")) return false;
	if (!testValue(form.hArea,"Basic Size (height)")) return false;
	if (!testValue(form.wArea,"Basic Size (width)")) return false;
	CalculateLinearFeet(form.rWeight.value,form.rWidth.value,form.hArea.value,form.wArea.value,form.bWeight.value);

	CalculateLinearYards(form.rWeight.value,form.rWidth.value,form.hArea.value,form.wArea.value,form.bWeight.value);

	return true;
}

function CalculateLinearFeet(rWeight,rWidth,hArea,wArea,bWeight) {
	var LinearFootage = (rWeight * (hArea * wArea) * 500) / (bWeight * rWidth * 12);
	document.lftForm.Answer1.value = formatnumber(LinearFootage,0);
}

function CalculateLinearYards(rWeight,rWidth,hArea,wArea,bWeight) {
	var LinearYardage = ((rWeight * (hArea * wArea) * 500) / (bWeight * rWidth * 12)) / 3;
	document.lftForm.Answer2.value = formatnumber(LinearYardage,0);
}


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.lftForm;
	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; }
}