Private Sub txt1_KeyPress(Index As Integer, KeyAscii As Integer) 
  .... 
  If <font color=red>Dez</font> = "," And KeyAscii = 46 Then 
    KeyAscii = 0 
  End If 
  ...
End Sub

Private Sub txt1_KeyPress(Index As Integer, KeyAscii As Integer) 
  .... 
  If Dez =  "," And KeyAscii = 46 Then KeyAscii = 44
  If Dez = "." And KeyAscii = 44 Then KeyAscii = 46
  ...
End Sub