Module Module1
    Public myform1 As Form1
    Public Sub main()
        ' DB öffnen usw.
        myform1 = New Form1()
        Application.Run(myform1)
    End Sub
End Module

Public Class Form1
    Inherits System.Windows.Forms.Form
 
#Region " Windows Form Designer generated code "
 
    Public Sub New()
        MyBase.New()
 
        'This call is required by the Windows Form Designer.
        InitializeComponent()
 
        'Add any initialization after the InitializeComponent() call
 
    End Sub
 
    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub
 
    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer
 
    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    Friend WithEvents MainMenu1 As System.Windows.Forms.MainMenu
    Friend WithEvents Menu_Start As System.Windows.Forms.MenuItem
    Friend WithEvents Menu_Start_Form2 As System.Windows.Forms.MenuItem
    Friend WithEvents MenuItem1 As System.Windows.Forms.MenuItem
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.MainMenu1 = New System.Windows.Forms.MainMenu()
        Me.Menu_Start = New System.Windows.Forms.MenuItem()
        Me.Menu_Start_Form2 = New System.Windows.Forms.MenuItem()
        Me.MenuItem1 = New System.Windows.Forms.MenuItem()
        '
        'MainMenu1
        '
        Me.MainMenu1.MenuItems.AddRange(New System.Windows.Forms.MenuItem() _
          {Me.Menu_Start})
        '
        'Menu_Start
        '
        Me.Menu_Start.Index = 0
        Me.Menu_Start.MenuItems.AddRange(New System.Windows.Forms.MenuItem() _
          {Me.Menu_Start_Form2, Me.MenuItem1})
        Me.Menu_Start.Text = "Start"
        '
        'Menu_Start_Form2
        '
        Me.Menu_Start_Form2.Index = 0
        Me.Menu_Start_Form2.Text = "Start form2"
        '
        'MenuItem1
        '
        Me.MenuItem1.Index = 1
        Me.MenuItem1.MdiList = True
        Me.MenuItem1.Text = "Open Windows"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(292, 266)
        Me.IsMdiContainer = True
        Me.Menu = Me.MainMenu1
        Me.Name = "Form1"
        Me.Text = "Form1"
 
    End Sub
 
#End Region
 
    Private Sub Menu_Start_Form2_Click(ByVal sender As System.Object, ByVal e _
      As System.EventArgs) Handles Menu_Start_Form2.Click
        Dim f2 As New Form2()
        f2.MdiParent = Me
        f2.Show()
    End Sub
End Class