Comparing two XML files in C#

[Chris]

Hallo everybody,

I have the following problem. There are two XML files: first one
(FIRST.xml) includes all products definition, the second one
(SECOND.xml) is a product instance. What do I need is to compare these
two files.

Let's see an example:

FIRST.xml
<Product ID="">
<Element ID=""/>
<Element ID=""/>
.....
<Element ID=""/>
</Product>

SECOND.xml
<Root>
<Products>
<Product ID="">
<Module Name=""/>
<Module Name=""/>
...
<Module Name=""/>
</Product>
...
<Product ID=""/>
</Products>
<Modules>
<Module Name="">
<Element ID=""/>
<Element ID=""/>
...
<Element ID=""/>
</Module>
...
<Module Name=""/>
</Modules>
</Root>

What do I need to do is find appropriate Product from SECOND.xml. If I
have it then there is a need to find all Modules content (all ELements)
of this Product and finally to compare FIRST.xml with the processed
information. Could you provide some C# source code to solve it ?

It is the first step of little bit more complicated problem.

Thanks in advance for the help
Chris