<?xml version="1.0" encoding="utf-8" ?>
<?xml-stylesheet type="text/xsl" href="pages.xsl" ?>   
  <root>   
  <user>ssm1226-1</user>   
  <user>ssm1226-2</user>   
  <user>ssm1226-3</user>   
  <user>ssm1226-4</user>   
  <user>ssm1226-5</user>   
  <user>ssm1226-6</user>   
  </root>   
怎样通过xsl求得<root>下<user>循环次数，得到6？