New Post: Set auto to Bottom

Hello
i am using AvalonDock LayoutAnchorablePane in my project.

<avalonDock:DockingManager x:Name="AnchorSide" Margin="0,0,0,0"        >
                                    <avalonDock:DockingManager.Theme>
                                        <avalonDock:Vs2013DarkTheme/>
                                    </avalonDock:DockingManager.Theme>
                                     
                                    <avalonDock:LayoutRoot >

                                        <avalonDock:LayoutPanel Orientation="Vertical">


                                            

                                            <avalonDock:LayoutAnchorablePaneGroup   >
                                                <avalonDock:LayoutAnchorablePane>
                                                    <avalonDock:LayoutAnchorable ContentId="iNotes"  Title="Notes"  CanFloat="true"  CanAutoHide="True" x:Name="NotesPane"   >
                                                        <TextBlock Height="30"  Background="#383838"/>
                                                    </avalonDock:LayoutAnchorable>
                                                    <avalonDock:LayoutAnchorable ContentId="messages" Title="Messages"   CanFloat="true"  CanAutoHide="True"  x:Name="MessagePane"  >
                                                        <TextBlock Height="30"  Background="#383838"/>
                                                    </avalonDock:LayoutAnchorable>
                                                    <avalonDock:LayoutAnchorable ContentId="feeds" Title="Feeds" CanFloat="true"     CanAutoHide="True"    x:Name="FeedsPane"    >
                                                        <TextBlock Height="30"  Background="#383838"/>
                                                    </avalonDock:LayoutAnchorable>
                                                </avalonDock:LayoutAnchorablePane>
                                            </avalonDock:LayoutAnchorablePaneGroup>
                                        </avalonDock:LayoutPanel>


                                    </avalonDock:LayoutRoot>

                                </avalonDock:DockingManager>
                               

When i click on Auto Hide, the Minimize Header still fixed on the right side of my application.
How can i set it to always display at bottom ?
thanks for your help