Modifying a variable while merging 2 XMLs documents !?

Hello 
 
Here is the context :
- I have one XML document which contains my software messages, translated in several languages. 
- I have one XML glosary with the translated messages for english, french and a new supported language (nl)
- I want to includes in the first document the new available translation
 
The basic criteria is : If english and french messages match, than insert the dutch translation.
The point is that in the glossary, some terms are repeated (cf. "CrC)er/Create")
So, once I have found one matching item to copy, I do not want to insert a 2nd translation.
For that, I used a variable which I change once I copy.

But it does not work ...

What is the mistake I made ? 
Is the a more consise way to do that work (no variable for value_fr and value_en) ? 


Thank you in advance 

JC)rC4me 
 
My software messages : 
<STR-Dictionary name="dic000-dial">
  <entry name="Dic_Create">
    <value xml:lang="fr">CrC)er</value>
    <value xml:lang="en">Create</value>
    <value xml:lang="es">Crear</value>
    <value xml:lang="pt">Criar</value>
    <value xml:lang="it">Crea</value>
    <value xml:lang="ja">C$B=EC&KB</value>
    <value xml:lang="de">Neu</value>
    <value xml:lang="zh-TW">C%B;B:C'B+b9</value>
    <value xml:lang="zh-CN">C%B;B:C'B+b9</value>
  </entry>
  <entry name="Dic_Rename">
    <value xml:lang="fr">Renommer</value>
    <value xml:lang="en">Rename</value>
    <value xml:lang="es">Renombrar</value>
    <value xml:lang="pt">Renomear</value>
    <value xml:lang="it">Rinomina</value>
    <value xml:lang="ja">C%BB
C%b0B
$,2>NC%B$b0C&b:B4(B</value>
    <value xml:lang="de">Umbenennen</value>
    <value xml:lang="zh-TW">C&b:B4C%BB
</value>
    <value xml:lang="zh-CN">C&b:B4C%BB
</value>
  </entry>
</STR-Dictionary>
 
The translated glossary : 
<glossary>
  <entry name='ID_2'>
    <value xml:lang='fr'>CrC)er</value>
    <value xml:lang='en'>Create</value>
    <value xml:lang='nl'>Aanmaken</value>
  </entry>
  <entry name='ID_3'>
    <value xml:lang='fr'>Supprimer</value>
    <value xml:lang='en'>Delete</value>
    <value xml:lang='nl'>Verwijderen</value>
  </entry>
  <entry name='ID_6'>
    <value xml:lang='fr'>Renommer</value>
    <value xml:lang='en'>Rename</value>
    <value xml:lang='nl'>Hernoemen</value>
  </entry>
  <entry name='ID_8'>
    <value xml:lang='fr'>Ouvrir</value>
    <value xml:lang='en'>Open</value>
    <value xml:lang='nl'>Openen</value>
  </entry>
  <entry name='ID_941'>
    <value xml:lang='fr'>CrC)er</value>
    <value xml:lang='en'>Create</value>
    <value xml:lang='nl'>Aanmaken</value>
  </entry>
</glossary>

My XSL Transformation : 
<xsl:stylesheet version="1.0"
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <!-- identity template -->
  <xsl:import href="copie.xslt"/>
  <xsl:output method="xml"  encoding="utf-8" indent="yes"/>
  <xsl:variable name="doc2"   select="document('glossaryNL.xml')"/>
  <xsl:template match="entry">
    <xsl:variable name="value_fr" select="current()/value[@xml:lang='fr']"/>
    <xsl:variable name="value_en" select="current()/value[@xml:lang='en']"/>
    <xsl:variable name="value_nl" select="current()/value[@xml:lang='nl']"/>
    <xsl:variable name="no_value_nl" select="string-length ($value_nl) &lt; 1"/>
    <xsl:copy>
      <!-- Copy existing stuff .. -->
      <xsl:apply-templates select="@*|node()"/>
      <xsl:for-each select="$doc2/*/*">
        <!-- If 'fr' and 'en' text elements match  ... -->
        <xsl:if test="    ./value[@xml:lang='fr'] = $value_fr
                      and ./value[@xml:lang='en'] = $value_en">
 
          <xsl:if test="$no_value_nl">
     <!-- If no translation yet, append it ..-->
     <xsl:copy-of select="./value[@xml:lang='nl']"/>
     <xsl:variable name="no_value_nl" select="false"/>
   </xsl:if>
 
        </xsl:if>
      </xsl:for-each>
    </xsl:copy>
  </xsl:template>
</xsl:stylesheet>

The result I get : 
<STR-Dictionary name="dic000-dial">
  <entry name="Dic_Create">
    <value xml:lang="fr">CrC)er</value>
    <value xml:lang="en">Create</value>
    <value xml:lang="es">Crear</value>
    <value xml:lang="pt">Criar</value>
    <value xml:lang="it">Crea</value>
    <value xml:lang="ja">C$B=EC&KB</value>
    <value xml:lang="de">Neu</value>
    <value xml:lang="zh-TW">C%B;B:C'B+b9</value>
    <value xml:lang="zh-CN">C%B;B:C'B+b9</value>
  <value xml:lang="nl">Aanmaken</value>
<value xml:lang="nl">Aanmaken</value>
</entry>
  <entry name="Dic_Rename">
    <value xml:lang="fr">Renommer</value>
    <value xml:lang="en">Rename</value>
    <value xml:lang="es">Renombrar</value>
    <value xml:lang="pt">Renomear</value>
    <value xml:lang="it">Rinomina</value>
    <value xml:lang="ja">C%BB
C%b0B
$,2>NC%B$b0C&b:B4(B</value>
    <value xml:lang="de">Umbenennen</value>
    <value xml:lang="zh-TW">C&b:B4C%BB
</value>
    <value xml:lang="zh-CN">C&b:B4C%BB
</value>
  <value xml:lang="nl">Hernoemen</value>
</entry>
</STR-Dictionary>