Joing data from XML files

[keioGirl]

I would like to know how can I join two XML files as we used to do in databases. Say I have two XMLs like:

<Students>
<student>
<name>John</name>
<school id="1">NTU</school>
</student>
<student>
<name>Jame</name>
<school id="2">NUS</school>
</student>
</Students>

and

<schoolList>
<school id="1">
<name>NTU</name>
<address zipcode="111-2333"> Singapore</address>
<phone>566-1463</phone>
</school>
<school id="2">
<name>NUS</name>
<address zipcode="112-8610">Singapore</address>
<phone>3943-0987</phone>
</school>
</schoolList>

And the result I would like to get is:

<Seminars>
<seminar id=”1”>
<name>John</name>
<school id=”1”>NTU</school>
<address zipcode="111-2333"> Singapore</address>
<phone>566-1463</phone>
</seminar>
<seminar id=”2”>
<name>Jame</name>
<school id="2">NUS</school>
<address zipcode="112-8610">Singapore</address>
<phone>3943-0987</phone>
</seminar>
</Seminars>

Thanks