conditional element counting

I would like to count the number of nodes that have an element containing a
specific element value.  Can this be done in XSL?  I couldn't find this in
the archive so I apologize if this has been posted before?

Suppose I have an XML file that looks like this:

<Rootnode>
  <Person>
    <Name>Joe</Name>
    <Age>10</Age>
  </Person>
  <Person>
    <Name>John</Name>
    <Age>10</Age>
  </Person>
  <Person>
    <Name>Sam</Name>
    <Age>18</Age>
  </Person>

I want to use XSL to count and display the number of Person nodes that have
an Age element with value = 10.  Is this possible?

Thanks,
Darren


 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list