<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:msxsl="urn:schemas-microsoft-com:xslt"
xmlns:user="whatever">

<msxsl:script implements-prefix="user" language="Javascript">
<![CDATA[
    function getDocURL(nodelist,sName) {
    if (sName == null)
  return "";

  var url = nodelist.nextNode().url;
  var re = new RegExp("[?&]" + sName + "=([^&]*|$)","i");

  if (re.test(url))
  return RegExp.$1;
  else
          return "";
    }
]]>
</msxsl:script>

<xsl:output method="text" indent="yes"/>

<xsl:template match="/">

****<xsl:value-of select="user:getDocURL(/,'varid')"/>****

</xsl:template>

</xsl:stylesheet>