Ssemi™ wrote:

> here xml data
> 
> <section title="country" view="1">
>    <submenu title="Bangkok">
>    <submenu title="Manila">
>    <submenu title="Cebu">
> </section


Consider to post well-formed XML, the above is far from being 
well-formed. Assuming the XML is as follows:

<section title="country" view="1">
    <submenu title="Bangkok"/>
    <submenu title="Manila"/>
    <submenu title="Cebu"/>
</section>


> xsl data
> 
> <xsl:template match="/">
> 	<xsl:apply-templates select="//section" />
> </xsl:template>
> 
> <xsl:template match="section">
>     <xsl:variable name="viewnum" select="@view" />
>      <xsl:value-of select="submenu[$viewnum]/@title" />
> </xsl:template>
> 
> result
>     Nothing.

then I can't reproduce the problem with the following stylesheet:

<xsl:stylesheet
   xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
   version="1.0">

   <xsl:template match="/">
	<xsl:apply-templates select="//section" />
</xsl:template>

<xsl:template match="section">
     <xsl:variable name="viewnum" select="@view" />
      <xsl:value-of select="submenu[$viewnum]/@title" />
</xsl:template>

</xsl:stylesheet>

as it does not output nothing but rather 'Bangkog'.

However doing submenu[$viewnum]/@title is probably not what you want, 
you rather want
   submenu[position() = $viewnum]/@title
as that way you get what you want, namely you select the 'title' 
attribute value for that 'submenu' element which is at position $viewnum 
of all 'submenu' child elements.

Doing
   submenu[$viewnum]
where $viewnum is a string as in your case would convert that string to 
a boolean value and any non-empty string converts to true meaning
   submenu[$viewnum]
is
   submenu[true()]
which is the same as
   submenu
and finally
   <xsl:value-of select="submenu[$viewname]/@title
would always output the 'title' attribute of the first 'submenu' child.

-- 

	Martin Honnen --- MVP XML
	http://msmvps.com/blogs/martin_honnen/