function calculatevat()
{
	var vatrate= Number(formVatcalc.nVatRate.value);
	var netcost = Number(formVatcalc.nNetCost.value);

	var VAT = ((vatrate / 100) * netcost);
	var grossvalue = formatnumber((netcost + VAT));

	formVatcalc.txtGross.value = formatnumber(grossvalue);
	formVatcalc.txtVAT.value = VAT;
}

function formatnumber(n)
{
	return Math.round(n*100)/100;
}