Private Sub TextBox2_KeyPress(ByVal sender As Object, ByVal e As _
  System.Windows.Forms.KeyPressEventArgs) Handles TextBox2.KeyPress
        Select Case Len(TextBox2.Text) ' Nur Uhrzeit in Textbox zulassen 
 
            Case 0
 
                Select Case Asc(e.KeyChar)
                    Case 8, 48 To 50
 
                    Case Else
                        e.Handled = True
                End Select
 
            Case 1
 
                If (TextBox2.Text) = 2 Then
                    Select Case Asc(e.KeyChar)
                        Case 8, 48 To 51
 
                        Case Else
                            e.Handled = True
                    End Select
                Else
                    Select Case Asc(e.KeyChar)
                        Case 8, 48 To 57
 
                        Case Else
                            e.Handled = True
                    End Select
                End If
 
            Case 2
 
                Select Case Asc(e.KeyChar)
                    Case 8, 48 To 53, 58
 
                        If Asc(e.KeyChar) <> 58 Then TextBox2.Text = _
                          TextBox2.Text & ":" ' Automatisches einfügen des 
                        ' Doppelpunktes 
                        Me.TextBox2.SelectionStart = Len(Me.TextBox2.Text) + 2
 
                    Case Else
                        e.Handled = True
                End Select
 
            Case 3
 
                If (TextBox2.Text) = ":" Then
                    Select Case Asc(e.KeyChar)
                        Case 8, 48 To 53
 
                        Case Else
                            e.Handled = True
                    End Select
                End If
 
            Case 4
                Select Case Asc(e.KeyChar)
                    Case 8, 48 To 57
                    Case Else
                        e.Handled = True
                End Select
            Case Else
                e.Handled = True
        End Select