equation border and background color

[Mansour <mansour77@yahoo.com>]

I am trying to put a border around the equations with background color. 
I need to align the equation in the center. I don't want the title 
inside the borders. I have tried this :
http://sources.redhat.com/ml/docbook/2003-07/msg00198.html

<xsl:attribute-set name="equation.properties" 
use-attribute-sets="formal.object.properties">
         <xsl:attribute name="border-color">#000000</xsl:attribute>
         <xsl:attribute name="border-style">solid</xsl:attribute>
         <xsl:attribute name="border-width">1px</xsl:attribute>
         <xsl:attribute name="padding">1em</xsl:attribute>
         <xsl:attribute name="background-color">#dddddd</xsl:attribute>
</xsl:attribute-set>

This surrounded the whole thing, the equation and the title.
Then from this page http://www.dpawson.co.uk/docbook/styling/params.html 
I tried to use :

<xsl:attribute-set name="shade.verbatim.properties">
   *border*-color="thin black ridge"
   background-color="silver"
</xsl:attribute-set>

But nothing happened.
 From this page http://www.sagehill.net/docbookxsl/AddNewTemplate.html I 
used :
        <xsl:template match="equation">
                <fo:block padding="5pt">
                        <xsl:attribute name="border">0.5pt solid 
blue</xsl:attribute>
                        <xsl:apply-templates />
                </fo:block>
        </xsl:template>

The title disappeared!
I used <xsl:apply-imports />. again the whole thing is wrapped inside 
the border.
Is there a way to get this done and align the block in the middle of the 
page?

Thank you.