input中value值与xsl:value-of 的有关问题

<xsl:for-each select="../SearchByUser/UserEmail">
??? ??? ??? <input type="hidden" name="searchtype" value="byuseremail"/>
??? ??? ??? <input type="hidden" name="searchvalue" >
??? ??? ??? ??? ??? ??? ??? ??? <xsl:attribute name='value'>
??? ??? ??? ??? ??? ??? ??? ??? ??? <xsl:value-of select="."/>
??? ??? ??? ??? ??? ??? ??? ??? </xsl:attribute>
??? ??? ??? </input>
</xsl:for-each>