Can't save a node tree in a variable.

Can you please help me?I want to save the sorted tree in a variable.
Whats wrong with the following xsl:
<xsl:variable name="sorted">
		<xsl:apply-templates mode="copy" select="data/item"/>
	</xsl:variable>
	<xsl:template match="@*|node()">
		<xsl:copy>
			<xsl:apply-templates select="@*|node()" mode="copy">
				<xsl:sort select="@sector"/>
				<xsl:sort select="@subsector"/>
			</xsl:apply-templates>
		</xsl:copy>
	</xsl:template>