Problem with white-spaces

[gu...@teleco.upv.es]

Hi friends,I am using the following xsp file where i get a value from a
session called "file".

<?xml version="1.0" encoding="ISO-8859-1"?>
<?cocoon-process type="xsp"?>
<?cocoon-process type="xslt"?>
<?xml-stylesheet  href="frames2.xsl" type="text/xsl"?>


<xsp:page language="java"
xmlns:xsp="http://www.apache.org/1999/XSP/Core">
       <SESSION>
       <xsp:logic>
        session=request.getSession(true);
        String done=(String)session.getValue("file");
        </xsp:logic>
        <xsp:expr>done</xsp:expr>
        </SESSION>
  </xsp:page>


After that i use the value of "file" to call a file. This file is called
{file}.xml whwre {file} means the value of the parameter. 

My xsl file is :

<xsl:strip-space elements="SESSION"/>

    <xsl:template match="SESSION">
      <xsl:variable name="prueba">
           <xsl:value-of select="."/>
       </xsl:variable>
       <FRAMESET  cols="20%,*">

            <FRAME src="{$prueba}.xml" frameborder="1"
marginwith="5"                noresize="" scrolling="automatic"
marginheigth="25"/>


            <FRAME name="center" src="acabando.xml"
frameborder="1"             marginwith="15"  scrolling="automatic"
marginheigth="25"/>
        </FRAMESET>	 
      </xsl:template>    
   
  </xsl:stylesheet>

Even using xsl:strip-space="SESSION" at the top the templates a lot of
white spaces are kept. 
Someone knows how to figure out this problem? Is it a problem of XSP?

Thanks in advance