disable-output-escaping

Hello friends,
I'm trying to avoid to have & as output.
So I use <xsl:text disable-output-escaping='yes'>&amp;nbsp;</xsl:text> .
I don't know if it's the right thing to do.
Is there a way to set it up only once in my stylesheet instead of using the
same expression every single time?

I'm trying to avoid to have &amp; as output in my URI(s) (ie:
http://server/tmp.jsp?a=1&amp;b=2)

Please help ...