> I would like to use a variable out of it scope.

You can't.


> <xsl:template match="level_2">
> <!-- How could I use "my_var" ? -->
> </xsl:template>

Some processors have extension functions that allow this (saxon:assign
being one of the guilty parties) but the design of XSLT is totally
influenced by the fact that it is a side effect free language.

It's not that imperative programming is necessarily evil, but if you
want to program in that style it makes more sense to use a language that
has assignment statements (omnimark, perl, ....) rather than trying to
twist a language that does not.

If you said what you were trying to do at a higher level, perhaps
someone may suggest how it would be done more naturally in XSLT.

David

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