how to include an ampersand in an html href using xt and xsl

I'm trying to generate an href like...

<a href="foo&bar">xxx</a>

using xsl similar to...

<a>
 <xsl:attribute name="href"><xsl:text
disable-output-escaping="yes">foo&bar</xsl:text>
 </xsl:attribute>
</a>

and a variety of permutations on this theme.

Section 16.4 of XSLT "Disabling Output Escaping" seems to say that
putting ampersands in attributes is flat-out illegal!  ("Thus, it is an
error to disable output escaping for an ... xsl:text element that is
used ot generate the string-value of a ... attribute node")

But & is a common character in href's.

I must be missing something somewhere.

Thanks in advance for any suggestions.


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