Somewhat offtopic: xsl question

Hi. 


    I'm making a UBLInvoiceToEDIFACT stylesheet. I need to count the number
of segments in the EDI file. What is the best way to do that in xsl (since
the faqs say there is no direct way to define and change a global var)? 

    I'm using javascript extensions, but would like to avoid that if
possible .


    Thanks


    Pedro Alves