xslt, fn:subsequance, java transformation
===

I have XML data  

	   <logData>
	      <log>
		     <id>1</id>
		  </log> 
	      <log>
		     <id>2</id>
		  </log> 
	      <log>
		     <id>3</id>
		  </log> 
	      <log>
		     <id>4</id>
		  </log> 
	   </logData>  
  
I want get only part of logs using xslt transformation using fn:subsequence function  
  
here is my xslt   

  

    <?xml version="1.0" encoding="UTF-8"?> 
        <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:fn="http://www.w3.org/2006/xpath-functions" version="1.0" >
           <xsl:output method="xml" indent="yes" />     
           <xsl:strip-space elements="*"/>
        
           <xsl:template match="/logData" >
              <xsl:element name="log">
                 <xsl:copy-of select="fn:subsequence(./log, 2, 3)"/>
              </xsl:element>
           </xsl:template>
        </xsl:stylesheet>   
      

and I get   

    ERROR:  'The first argument to the non-static Java function 'subsequence' is not a valid object reference.'  
  
I am using Java transformation API, part of Java SE 1.6.  
Can you help me? 

