xsl:if formatting problem

I have a stylesheet which optionally takes a parameter to offset the
header xml file which I am importing by a certain percent.  However I am
having trouble getting the xsl:if to work. 
I am using XT on Solaris 2.6, JDK 1.2.

The error is 
file:/usr/users/pdp/webs/stylesheets/general.xsl:59: mismatched end tag:
expected "td" but got "xsl:if"

I realize it wants me to close the td but I want to close it later.  What
is the way around this?  Alternatively it seems I have to write many more
compound tests testing for different scenarios of $centeroffset and
@header.

Thanks for any help.  My code is below:

   <xsl:if test="string-length($centeroffset)>0">
      <table width="100%">
      <tr>
         <td width="{$centeroffset}"/>
         <td>
   </xsl:if>
   <xsl:if test="string-length(@header)=0">
      <xsl:apply-templates select="document($header-fancy)"/>
   </xsl:if>
   <xsl:if test="string-length(@header)>0">
      <xsl:apply-templates select="document($header)"/>
   </xsl:if>
   <xsl:if test="string-length($centeroffset)>0">
      </td></tr></table>
   </xsl:if>



Phil Padgett                         Coordinator Computer Applications
pdp@xxxxxxxxxxxxxxx                  Division of Biostatistics
http://www.biostat.ufl.edu/~pdp      University of Florida


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