Public Class Pupil
      Private myName As String
      Private myId As Integer
 
      Public Sub New(ByVal Name As String, ByVal ID As Integer)
         myName = Name
         myId = ID
      End Sub
 
      Property ID() As Integer
         Get
            Return myId
         End Get
         Set(ByVal value As Integer)
            myId = value
         End Set
      End Property
 
      Property Name() As String
         Get
            Return myName
         End Get
         Set(ByVal value As String)
            myName = value
         End Set
      End Property
 
      Public Sub ChangeName(ByVal newname As String)
         myName = newname
      End Sub
   End Class
 
   Public Class Seminar
      Private myPupils As List(Of Pupil)
      Private myID As Integer
      Private myName As String
 
      Public Sub New(ByVal Name As String, ByVal ID As Integer)
         myPupils = New List(Of Pupil)
         myName = Name
         myID = ID
      End Sub
 
      Public Sub AddPupil(ByVal Name As String)
         myPupils.Add(New Pupil(Name, myPupils.Count))
      End Sub
 
      Public Sub ChangeName(ByVal NewName As String)
         myName = NewName
      End Sub
 
      Public Function GetPupilByID(ByVal SearchID As Integer) As Pupil
         Return myPupils(SearchID)
      End Function
 
      Public Property ID() As Integer
         Get
            Return myID
         End Get
         Set(ByVal value As Integer)
            myID = value
         End Set
      End Property
 
      Public Property Name() As String
         Get
            Return myName
         End Get
         Set(ByVal value As String)
            myName = value
         End Set
      End Property
 
      Public ReadOnly Property Pupils() As List(Of Pupil)
         Get
            Return myPupils
         End Get
      End Property
   End Class
 
   Public Class SchoolHandler
      Private mySeminars As List(Of Seminar)
 
      Public Sub New(ByVal StartID As Integer)
         mySeminars = New List(Of Seminar)
      End Sub
 
      Public Sub Add(ByVal Name As String)
         mySeminars.Add(New Seminar(Name, mySeminars.Count))
      End Sub
 
      Public Function GetSeminarByID(ByVal SearchID As Integer) As Seminar
         Return mySeminars(SearchID)
      End Function
 
      Public Sub ShowAllPupils()
         For Each CurrSem As Seminar In mySeminars
            Debug.Print(CurrSem.Name)
 
            For Each CurrPup As Pupil In CurrSem.Pupils
               Debug.Print(CurrPup.Name)
            Next
 
            Debug.Print(vbNewLine)
         Next
      End Sub
   End Class
 
   Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As  _
     System.EventArgs) Handles MyBase.Load
 
      Dim school As New SchoolHandler(1)
 
      school.Add("Mathe")
      school.Add("Deutsch")
 
      school.GetSeminarByID(0).AddPupil("Hans")
      school.GetSeminarByID(1).AddPupil("Bernd")
 
      school.ShowAllPupils()
 
      school.GetSeminarByID(0).GetPupilByID(0).Name = "Georg" ' EDIT
      school.GetSeminarByID(0).Name = "Sport" ' EDIT
 
      school.ShowAllPupils()
   End Sub