[xml] multiple XPath evaluations on the same document

[IRENE SIPIKA <piotreks optonline net>]

I have a question regarding multiple XPath evaluations on the same 
document, specifically:
Assuming the base document is as follows:
<root>
  <parameter id="1"/>
  <parameter id="2"/>
  <element name="kid1">
     <parameter id="1"/>
  </element>
  <element name="kid2">
      <parameter id="1"/>
      <parameter id="2"/>
      <parameter id="3"/>
  </element>
</root>

I know I can retrieve all root::parameter nodes by allocating a new 
xpath context for the document and then evaluating the expression 
'/root/parameter'.

Let's say I traverse the document and am now at element with 
name="kid2", how do I use the same, already allocated xpath context to 
find all element::parameter nodes?
Do I have to specify the element name attribute in the query 
('/element[ name='kid2']/parameter')?
Or is there a way for me to use the current 'element' node as the root 
for the next xpath query?
(trying to avoid creating a new context for each of the queries on the 
same document)


Thanks very much.
Piotrek