This works well with the XML file and retreives unique values.
<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl
utput method="xml" />
<xsl:template match="/">
<EmployeeName>
<xsl:for-each select="/HumanResources/Employee/Name[not(.=preceding::Name)]">
<Name><xsl:value-of select="."/></Name>
</xsl:for-each>
</EmployeeName>
</xsl:template>
</xsl:stylesheet>
Refer
http://www.eggheadcafe.com/articles/20010508.asp for details.
Hope this helps.
Vasudha