GetDockableWindow return Nothing

Discussion created by valraa on Dec 14, 2010
Latest reply on Dec 15, 2010 by chump4life
I create e DockableWindow with a visualstudio NET tool for arcgis.
But using this code "m_dockableWindow" is Nothing:

Private Sub SetupDockableWindow()
        If m_dockableWindow Is Nothing Then
            Dim dockWindowManager As IDockableWindowManager
            dockWindowManager = CType(m_application, IDockableWindowManager)
            If Not dockWindowManager Is Nothing Then
                Dim windowID As UID = New UIDClass
                windowID.Value = DockableWindowGuid
                m_dockableWindow = dockWindowManager.GetDockableWindow(windowID)
            End If
        End If
    End Sub

If I use an example found on line by the same code still works!
Does anyone know help me?