I'll try again:-)

You haven't said what your input document looks like, but I'd guess
that it doesn't match the paths in your select expression.

<xsl:template match="/">
	<!-- snip -->
	<xsl:apply-templates>

so this apply templates applies to children of the root node.
There must be exactly one such child, and so xsl:sort has only got
a list of length one to sort.


You probably want to use

<xsl:template match="xxx">

where xxx is your document element.

If you do that then 

the apply templates applies to all the children of the document node.
 <xsl:sort select="*[local-name()=string($sortby)]"

is executed with those children being the current node, this the top
level sortby parameter should name a grandchild of the root, otherwise
the sort key will be null all the time.

If you want to use a sort key that returns a non null value for
the elements named by  $sortby you might want ti use

 <xsl:sort select="self::*[local-name()=string($sortby)]"

David


 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list