Ideas for creating quotation collection

Hello,

I plan to convert a quite big collection of quotations archived in XML to  
XHTML via XSL. Currently I am getting the job done with a Java-tool I've  
programmed.
What I want to do is group the quotes into categories (according to author  
(x)or content).
I've started with
<xsl:choose>
        <xsl:when test="contains(.,'Mark Twain')">
          <xsl:attribute name="category">Mark Twain</xsl:attribute>
        </xsl:when>
    ....
</xsl:choose>

I'd write the result of this transformation into a file and process that  
file with another XSL-sheet to produce the final XHTML-file.
I've two questions:
 The test should not be case-sensitive. How could I do that?

 Is there a better way of doing it - maybe not requiring two passes?



thanks & regards
Steffen