Combobox in TreeViewItem

[levik]

Hi all!

I'm newbie in WPF, so sorry about stupid question.
It is possible to show combobox side by side with selected TreeViewItem?
I need something like shown in the 1.jpg picture.
I tried to do thus:

        <TreeView Name="treeView1">   
            <TreeViewItem Header="aaa">   
                <ComboBox Height="19">   
                    <ComboBoxItem IsSelected="True">111</ComboBoxItem>  
                    <ComboBoxItem>222</ComboBoxItem>  
                    <ComboBoxItem>333</ComboBoxItem>  
                </ComboBox>  
                <TreeViewItem Header="aaa1">   
                </TreeViewItem>  
                <TreeViewItem Header="aaa2">   
                </TreeViewItem>  
            </TreeViewItem>  
            <TreeViewItem Header="bbb">   
                <TreeViewItem Header="bbb1" />  
                <TreeViewItem Header="bbb2" />  
            </TreeViewItem>  
            <TreeViewItem Header="ccc" />  
        </TreeView>

and the result you can see in the 2.jpg picture.

Meantime I need to know, how to do this visually. Later I need to do something with SelectedItemChanged event.

Thanks in advance!

P.S. sorry about my english