[xsl] No Duplicate Contain() is Allowed?

[Alice Wei <ajwei@xxxxxxxxxxx>]

Dear all:

   For those of you who may know something about SQL or XQuery might 
be able to help me out.

XML:
     <bookshelf>
     <book>XSLT 2.0: From Beginning to Professional
       <topic>XML</topic>
      <publisher>Wiley</publisher></book>
     <book>XML in a Nutshell
     <publisher>Oreilly</publisher</book>
     <book>XSLT 2.0: Programmer's Reference
     <topic>XML</topic>
     <publisher>Wrox</publisher>
     </book>
     </bookshelf>

XSLT:

<xsl:template match="bookshelf">

       <xsl:if test="contains(//book/*, 'XML')">
           <xsl:apply-templates/>
       </xsl:if>
      <xsl:if test="contains(//topic/*, 'XML')">
         <xsl:apply-templates/>
     </xsl:if>
</xsl:template>


What happened is really weird. If I had commented out the 2nd <xsl:if> 
statement, it brings back one line without error. When I got to the 2nd 
one, it tells me this error: Description: A sequence of more than one 
item is not allowed as the first argument of contains() ("", "", ...)

My document is obviously well-formed, can anyone please give me some 
suggestions on how to get rid of this error?

Thanks to those who can help.

Alice


Alice Wei
MIS 2008
School of Library and Information Science
Indiana University Bloomington