using javascript in xsl

Hi!
I'm trying to set up an HTML-site based on an xml-file rendered with xsl. I would like to split the site in two frames by defining a javascript function().
Here's the code:

<xsl:template match="/">
<html>
<head>
<title>xml-generated module</title>
<meta http-equiv="Content-Type"
content="text/html; charset=iso-8859-1"/>
<script language="JavaScript">
<![CDATA[function mainframe() return "<html><body><xsl:apply-templates select="//titre" /></body></html>";}]]>
<![CDATA[function linkframe() {return"<html><body><span>Foo</span></body></html>";}]]>
</script>
</head>
<frameset cols="25%,75%" rows="100%" border="1">
<frame name="linkview" src="javascript

arent.mainframe();"/>
<frame name="mainview" src="javascript

arent.linkframe();"/>
</frameset>

</html>
</xsl:template>

Without javascript, everything is working fine.
Does anybody know what I'm missing?
Thanks for your help.
Regards, Nathalie