> Let's say I have an XMl file which has an element such as:
> <include url="file.xml"/>
> This file would be part of the "input tree".
> You would probably say that xsl:include would do the trick, 
> yes but that's
> not my question.
> We want to make these inclusions conditional, and than work 
> on that result
> tree.

If I understand what you need, you could use the document() function
together with xsl:if or xsl:choose. Not xsl:include, which can only be used
to include *stylesheets*, not XML source. documents. 

Linda




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