probleme cu meniu (xsl, xml, javascript)

salutare,

am o problema cu xsl. trebuie sa transform xml in html. Am incercat, toate apar bine, mai putin cind trebuie din datele selectate sa fac un meniu cu javascript.  

xml

		<Tree>
		 <Ebene ueebene="1">
			<UB>
			   <UeBez>Titel1</UeBez>
			   <UebKomentar>B.Sc.</UebKomentar>
			</UB>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text1</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text2</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text3</UeBez>
			   </UB>
			</Ebene>
		 </Ebene>
		 <Ebene ueebene="1">
			<UB>
			   <UeBez>Titel2</UeBez>
			   <UebKomentar>B.Sc.</UebKomentar>
			</UB>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text1</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text3</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text4</UeBez>
			   </UB>
			</Ebene>
		 </Ebene>
		 <Ebene ueebene="1">
			<UB>
			   <UeBez>Titel3</UeBez>
			   <UebKomentar>B.Sc.</UebKomentar>
			</UB>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text1</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text2</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text3</UeBez>
			   </UB>
			</Ebene>
		 </Ebene>
		 <Ebene ueebene="1">
			<UB>
			   <UeBez>Titel4</UeBez>
			   <UebKomentar>B.Sc.-NF</UebKomentar>
			</UB>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text1</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text2</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text3</UeBez>
			   </UB>
			</Ebene>
		 </Ebene>
		 <Ebene ueebene="1">
			<UB>
			   <UeBez>Titel5</UeBez>
			   <UebKomentar>B.Sc.-NF</UebKomentar>
			</UB>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text1</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text2</UeBez>
			   </UB>
			</Ebene>
		 </Ebene>
		 <Ebene ueebene="1">
			<UB>
			   <UeBez>Titel6</UeBez>
			   <UebKomentar>M.Sc.</UebKomentar>
			   <ZUebPostnotiz />
			</UB>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text1</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text2</UeBez>
			   </UB>
			</Ebene>
			<Ebene ueebene="2">
			   <UB>
				  <UeBez>text3</UeBez>
			   </UB>
			</Ebene>
		 </Ebene>
</Tree>

si xsl

<xsl:variable name="Fachnr" select="count(Tree/Ebene[@ueebene=1])"/>
 <script type="text/javascript">
				function setVisible(Fach_Nummer)
				{
				 		for (var i = 0; i &lt;=<xsl:value-of select="$Fachnr"/> ; i++)
				 {
				if (i != 0) {
				document.getElementById('Fach_' + i).style.display=(('Fach_' + i)==Fach_Nummer)?'inline' : 'none';}
	 					document.getElementById('Tab_' + i).style.fontWeight=(('Fach_' + i)==Fach_Nummer)?'600' : 'normal';
	 					document.getElementById('Tab_' + i).style.zIndex=(('Fach_' + i)==Fach_Nummer)?'100' : i;
				document.getElementById('Tab_' + i).className=(('Fach_' + i)==Fach_Nummer)? 'active' : 'inactive';
				 }
				 setKatVisible('TabKat_' + Fach_Nummer.substring(5));
				}
				
				function setKatVisible(Kat_Nummer)
				{
				 for (var i = 1; i &lt;=<xsl:value-of select="$Fachnr"/> ; i++)
				 {
				 document.getElementById('TabKat_' + i).style.display=(('TabKat_' + i)==Kat_Nummer)?'inline' : 'none';
				 }
				}
	</script>
<xsl:template name="navigare">
	<div id="lv-navigation" class="clearfix">
	   <div id="lv-navSus" class="clearfix">
		<div id="lv-navFach" class="clearfix">
		  <ul class="clearfix">
			<xsl:for-each select="Tree/Ebene[@ueebene=1]/UB[generate-id(.)=generate-id( key('Fach',UebKomentar)[1])]">
			<li><a>
			  <xsl:attribute name="id">Tab_<xsl:value-of select="position()"/></xsl:attribute>
			  <xsl:value-of select="UebKomentar"/></a></li>
			</xsl:for-each>
		  </ul>
		</div>
	  </div>
	  <div id="lv-navKategorie">
		<xsl:for-each select="Tree/Ebene[@ueebene=1]/UB[count(. | key('Fach',UebKomentar)[1])]">
		  <xsl:for-each select="key('Fach',UebKomentar)">
			<span class="lv-tabKategorie">
		<xsl:attribute name="id">TabKat_<xsl:value-of select="position()"/></xsl:attribute>
			<span class="lv-kat">
				<a>
				  <xsl:attribute name="href">
					#katAnker_<xsl:value-of select="generate-id(.)"/>
				  </xsl:attribute>
				  <xsl:value-of select="UeBez"/>
				</a>
			  </span>
			  </span>
		   </xsl:for-each>
		</xsl:for-each>
	  </div>
		  </div>
  </xsl:template>

normal, trebuie pe prima linie selectat dupa UebKomentar. Pentru fiecare UebKomentar sa apara pe linia a doua de meniu UeBez si pentru fiecare UeBez  pe linia a treia de meniu sa apara UeBez de pe Ebene ueebene="2". Momentan incerc primele 2 linii de meniu sa le creez, dar imi apare urmatoarea eroare

document.getElementById("Tab_" + i) is null

document.getElementById('Tab_' + i).style.fontWeight=(('Fach_' + i)==Fach_Nummer)?'600' : 'normal';

poate cineva sa-mi spuna unde ii greseala? sau am facut ceva gresit la selectare?  

Dana