Xalan and command-line parameters

I'm having trouble passing command-line parameters to a stylesheet, but
I've searched your archives and I can't find anything wrong with it, so
maybe someone can point out the problem.

I invoke the stylesheet like this:

xalan -IN chapters.xml -XSL param.xsl -OUT foo.txt \
      -PARAM myParameter the-value

------ stylesheet -----

<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

<xsl:output method="text"/>

<xsl:param name="myParameter"/>

<xsl:template match="/">
  <text>
You set the parameter to:
  </text>
<xsl:value-of select="$myParameter"/>
</xsl:template>

</xsl:stylesheet>

-- 
    People say I am ruthless. I am not ruthless. And if I find
    the man who is calling me ruthless, I shall destroy him.
         - Robert Kenedy, campaigning for the U.S. Senate in 1964