add node to xml file

Question

hello there!

i have a problem how to write to a xml file using the xmlpath technology

i have the following file books.xml

<books>
<A property="a">
<B>text</B>
<C>textg</C>
<D>99999</D>
</A>
</books>

i need to add to the file it self nodes, for example the E & F nodes how can i do it?

<books>
<A property="a">
<B>text</B>
<C>textg</C>
<D>99999</D>
<E>
<F>0000</F>
</E>
</A>
</books>

Thanks ahead