'Zu öffnendes Formular
        Dim frm As FMManagement = FMManagement.Instance
        frm.MdiParent = Me
        frm.Show()

    Private Sub ToolStrip_Zeige_Sendung_Click(ByVal sender As System.Object, _
      ByVal e As System.EventArgs) Handles ToolStrip_Zeige_Sendung.Click
    Dim vSENDUNGNR As Integer = Me.DGVWFEIDAL_SENDUNGEN.Item( _
    DGVWFEIDAL_SENDUNGEN.Row, "SENDUNGNR")
 
        Dim frm As FMSendungen= FMSendungen.Instance
        'Mein Hauptform mit eigenschaft IsMdiParent = true
        Dim Parent_Form As FMStart = FMStart
        frm.MdiParent = Parent_Form
        frm.Show()
    End Sub