Delete node from treeView when Attribute are similar

Am working on my first C# Winform application :( I browse an XML file to a treeView , then I selecte node and I wante do delete it ... Am doing it . My problem is : Each node contain an Id attribute , then this node is used two or tree time in the same file , ans i want to delete all the duplicate . this is an exp :

<list>
<object number="3" background_colour="7" id="2996" name="MyFirst" type="2">

    <child id="3794" x="0" y="0"/>
    <child id="13794" x="0" y="44"/>
    <child **id="13794**" x="239" y="44"/>
</object>

`

So, Now I can't delete node , but I want if i delete the object with id =13794 , I automaticlly delete also the Child with id =13794

I really think about this from one week :( if someone have an idea . thnks