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

	if (document.ppiForm.pCaliper.value == "")
		{
		alert("Enter Caliper of Paper.");
		document.ppiForm.pCaliper.focus();
		return (false);
		}

	if (isNaN(document.ppiForm.pCaliper.value))
		{
		alert("Caliper must be a valid number.");
		document.ppiForm.pCaliper.focus();
		return (false);
		}

	CalculatePPI(form.pCaliper.value);

	return true;
}

function CalculatePPI(pCaliper) {
	var ppi = 2 / pCaliper;
	document.ppiForm.Answer.value = formatNumber(ppi,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;
}