如何用xsl递归输出xml

xml文件：
C# code

<?xml version="1.0" encoding="utf-8"?>
<?xml-stylesheet type="text/xsl" href="style.xsl"?>
<page>
  <categories> 
    <category id="1" title="rootcate">
      <category id="2" title="z1j1"/>
      <category id="3" title="z1j2">
        <category id="4" title="z2j1"/>
        <category id="6" title="z2j2"/>
      </category>
      <category id="12" title="z1j3"/>
      <category id="14" title="z1j4"/>
    </category>
  </categories>
</page>

请问如何写xsl以生成这样的效果
rootcate
├z1j1
├z1j2
│├z2j1
│└z2j2
├z1j3
└z1j4

参考这里：http://blog.csdn.net/cds27/archive/2005/10/24/514457.aspx