Public lf As Integer, tp As Integer
    Private Sub Neue_Form()
        Dim frm As Form = New Form2
        frm.MdiParent = Me
        If lf + Me.MdiChildren(Me.MdiChildren.Length - 1).Width > Me.Width Then
            lf = 0
            tp += Me.MdiChildren(Me.MdiChildren.Length - 1).Height
        End If
 
        frm.Show()
 
        frm.Left = lf
        frm.Top = tp
        lf += Me.MdiChildren(Me.MdiChildren.Length - 1).Width
    End Sub