function onKeyPress()
{
	if ( ( document.getElementById("Pay").value.length == 0 ) || ( ( document.getElementById("TaxCode").value.length == 0 ) && ( document.getElementById("AdditionalCode").value != 'BR' ) ) )
	{
		document.getElementById("Calculate").disabled = true;
		document.getElementById("Calculate").style.color = 'lightgray';
	}
	else
	{
		document.getElementById("Calculate").disabled = false;
		document.getElementById("Calculate").style.color = 'white';
	}
}
function checkTaxCode(form)
{
	if(document.getElementById("TaxCode").value.length == 0)
	{
		if (document.getElementById("AdditionalCode").value != "BR")
		{
			window.alert("Please provide a tax code, or choose an additional tax code");
			return false;
		}
		
	}

}