[xsl] sorting based on variable and limit the results

[Michalmas <michalmas@xxxxxxxxx>]

Hi guys,

is it possible to sort based on xsl:variable? If so, how?

For example, i have such piece of code:
                                         <xsl:for-each select="//s">					
					    <xsl:variable name="name" select="n" />
						<xsl:variable name="quantity" select="count(//p/pp[(.) = $name])" />					
					   <tr>							
							<td><xsl:value-of select="n"/></td>							
							<td><xsl:value-of select="$quantity"/></td>
					   </tr>
					</xsl:for-each>

and i want to sort on $quantity (simple xsl:sort is not compilable).

And the second part of question - is it possible to limit the result
to the top 10, without intermediate representation (or, just in one
XSLT script).

Thanks!