[RESOLVED] Extract letters from a string contaning numbers

[isnoend07]

i have a regristraction routine that check for valid input
I thought the following would work, but if the user only entered numbers and no letters
it could be fooled, how can i make sure the proper letters are input ?

Private Sub Command5_Click()
    Dim Success As Boolean
    Dim Value As String
    Dim StringEntered As String
    StringEntered = "yjk65kg12dky" 'this will be textbox value entered by user
    Value = GetNumbers(StringEntered)
    
  If Val(Value) >= 5000 And Val(Value) <= 9900 Then
  'now check if the correct letters are typed
    Success = True
  Else
    Success = False
  End If
    MsgBox Success

End Sub
Function GetNumbers(Value As String) As String
'extract and return numbers from a string
    Dim Index As Long
    Dim Digit As String
    Dim Final As String
    Dim Count As Long
    
      Count = 1
      GetNumbers = space(Len(Value))
      For Index = 1 To Len(Value)
        Digit = Mid(Value, Index, 1)
        If Digit Like "[0-9]" Then
          Mid(GetNumbers, Count, 1) = Digit
          Count = Count + 1
        End If
      Next
    
      GetNumbers = Left(GetNumbers, Count - 1)
End Function