accessing an attribute value in a for-each loop

Why can I not access the @span value in the XSL below, first the XML:

 <table>
  <row header="table">
   <cell>Fase</cell>
   <cell>Activiteit</cell>
   <cell>Taakomschrijving</cell>
   <cell>Resultaten</cell>
   <cell>Tijdsperiode</cell>
   <cell>Go/no-gopunten</cell>
   <cell>Uitvoerders</cell>
  </row>
  <row header="phase">
   <cell span="2">whatever<b>Individual Components </b></cell>
   <cell span="4">Proceed </cell>
   <cell>1,3,4</cell>
   .... 

... and the XSL fragment:

<xsl:template match="table">
 <fo:table break-before="page">
  <fo:table-column column-width="100pt"/>
  <fo:table-column column-width="100pt"/>
  <fo:table-column column-width="75pt"/>
  <fo:table-column column-width="100pt"/>
  <fo:table-column column-width="75pt"/>
  <fo:table-column column-width="100pt"/>
  <fo:table-column column-width="100pt"/>
  <fo:table-body font-size="6pt" font-family="sans-serif">
   <xsl:for-each select="row">
    <fo:table-row>
     <xsl:for-each select="cell">
        <!-- <xsl:attribute name="number-columns-spanned">5</xsl:attribute> nope :( -->
        <fo:table-cell number-columns-spanned="{@span}" >
                                              ^^^^^^^^^
       <fo:block>

-- 
Eric Smith - using xalan and fop

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