<ToolBarTray DockPanel.Dock="Top"  >
    <ToolBar Name="toolbar1" Band="1"  >
        <Label Content="Nummer" Margin="5 0 5 0"/>
        <TextBox Width="60" Name="tNumber" Margin="5 0 5 0" >24</TextBox>
        <Button Name="BnInsertree" Margin="5 0 5 0" Background="WhiteSmoke" Click="BnInsertree_Click">Insert Tree</Button>         </ToolBar>
</ToolBarTray>