Public Class frmSample
    Inherits System.Windows.Forms
 
    Private Shared iCount as integer
 
    Public Sub New()
        MyBase.New()
 
        InitializeComponent()
 
        if iCount is Nothing then
            iCount = 1
        else
            iCount += 1
        End If
 
    Private Sub Form_Load(Sender as Object, e As eventargs) handles Form.Load
        if icount > 1 then
            me.close
        end if
 
        ' anderer load code
 
    End Sub
 
    PRivate Sub Dispose(parameterliste) handles form.dispose
        iCount -=1
 
        ' anderer dispose code
 
    End Sub 
End Class