function Back() {
	history.go( -1 );
}

function checkForm() {
	var iValue = document.getElementById( "txtCardNumber" ).value;
	if( ! isNumber( iValue ) ) {
		alert( "Kortnummeret indeholder ugyldige tegn." );
		return false;
	}
	iValue = document.getElementById( "CVC" ).value;
	if( ! isValue( iValue ) ) {
		alert( "Kontrolcifrene indeholder ugyldige tegn" );
		return false;
	}

	return true;
}

function openPrinterFriendly() {
	window.open( 'Shop/PrinterFriendly.aspx', '_blank', 'width=600, height=410, scrollbars=yes, toolbar=yes, status=yes, menubar=no' );
}