Sorting & duplicates

[A.T.]

Have an XSL file that flags duplicate id's, by painting cells blue and by adding the word "duplicate" to a new column at the end of the table. It also sorts the id's. Would like to have the output file retain these qualities, but also sort the document(using the duplicate column) so that duplicates come at the beginning.

XML file
<root>
<version size="16">
<id>A1</id>
<type>mac</type>
</version>
<version size="16">
<id>A1</id>
<type>mac</type>
</version>
<version size="32">
<id>A2</id>
<type>pc</type>
</version>
</root>
XSL file
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format">

<xsl:template match="/">
<html>
<head>
<title>Version Information</title>
</head>
<body>
<table border="1" align="center"
cellPadding="1"
cellSpacing="1">
<tr>
<th>Id</th>
<th>Size</th>
<th>Type</th>
<th>Duplicate</th>
</tr>
<xsl:apply-templates/>
</table>
</body>
</html>
</xsl:template>

<xsl:template match="root">
<xsl:apply-templates select="version">
<xsl:sort select="id"/>
</xsl:apply-templates>
</xsl:template>

<xsl:template match="version">
<tr align="center">
<xsl:choose>
<xsl:when test="child::id=preceding::id">
<td bgcolor="blue">
<xsl:value-of select="id"/>
</td>
</xsl:when>
<xsltherwise>
<td><xsl:value-of select="id"/></td>
</xsltherwise>
</xsl:choose>
<td><xsl:value-of select="@size"/></td>
<td><xsl:value-of select="type"/></td>
<xsl:choose>
<xsl:when test="child::id=preceding::id">
<td>duplicate</td>
</xsl:when>
<xsltherwise/>
</xsl:choose>
</tr>
</xsl:template>
</xsl:stylesheet>