Private Sub Login_KeyDown(ByVal sender As Object, _
        ByVal e As System.Windows.Forms.KeyEventArgs) _
            Handles tboUserName.KeyDown, tboPassWord.KeyDown
 
        Dim Usernames(2) As String
        Usernames(0) = "ICH" : Usernames(1) = "GAST"
        Dim Passwords(2) As String
        Passwords(0) = "START" : Passwords(1) = "BEGINN"
 
        If e.KeyCode = Keys.Return Then
            If tboUserName.Text.Trim = String.Empty Then
                MessageBox.Show("Geben Sie einen Benutzernamen ein")
                Exit Sub
            End If
            If tboPassWord.Text.Trim = String.Empty Then
                MessageBox.Show("Geben Sie Ihr Passwort ein")
                Exit Sub
            End If
 
            If Not Usernames.Contains(tboUserName.Text.ToUpper.Trim) Then
                MessageBox.Show("Unbekannter Benutzer")
                Exit Sub
            End If
 
            Dim userind As Integer = _
            System.Array.IndexOf(Usernames, tboUserName.Text.ToUpper.Trim)
 
            If Passwords(userind) <> tboPassWord.Text.ToUpper.Trim Then
                MessageBox.Show("Falsches Passwort")
            Else
                MessageBox.Show("Herzlich Willkommen " & Usernames(userind))
            End If
        End If
    End Sub