Check textbox contians "DWD" followed by 5 HEX characters?

Hi,

I'm using the below code to check my textbox has a value of "DWD" and 5 hex characters, e.g. DWD00A0A. It doesn't seem to work with the (5) after the HEX part of the validation, although it does work without the (5) in there, although it means users can enter more than 5 HEX characters.

can anyone see why this is not working?

Thanks,
Paul.

If Not Regex.IsMatch(Respond_DWD.Text, "^[D]{1}[W]{1}[D]{1}[A-Fa-f0-9](5)$") Then
            MessageBox.Show("Please enter users workstation id in the correct format (E.G. DWD1A2B3)." & vbNewLine & vbNewLine & "E.G. DWD00A0A")
End If

Select allOpen in new window