Private Sub Text1_KeyPress(KeyAscii As Integer)
   ' check for the lower case
   If ((KeyAscii >= 97 And KeyAscii <= 122) And KeyAscii <> 96) Then
       ' OK
       Exit Sub
       
   ' check for upper case
   ElseIf (KeyAscii >= 65 And KeyAscii <= 90) Then
       ' ok
       Exit Sub
   End If
   
   
   ' all not ok
   KeyAscii = 0
End Sub