Public Sub TextBoxVisualLock(TextBox As TextBox, _
 ByVal Locked As Boolean, _
 Optional ByVal ForeColor As Long = -1, _
 Optional ByVal BackColor As Long = -1)
 
  With TextBox
    .Locked = Locked
    Select Case Locked
      Case False
        If ForeColor = -1 Then
          .ForeColor = vbWindowText
        Else
          .ForeColor = ForeColor
        End If
        If BackColor = -1 Then
          .BackColor = vbWindowBackground
        Else
          .BackColor = BackColor
        End If
      Case True
        If ForeColor = -1 Then
          .ForeColor = vbWindowText
        Else
          .ForeColor = ForeColor
        End If
        If BackColor = -1 Then
          .BackColor = vb3DFace
        Else
          .BackColor = BackColor
        End If
    End Select
  End With
End Sub