Thank you for your advice.
I update my code as follows.

<xsl:param name="VariableNum" select="count(/Variable)"/>
  <script>
       <xsl:text> var Variable0 = new Array( </xsl:text>
       <xsl:value-of select="$VariableNum"/>
       <xsl:text> );</xsl:text>
  </script>

It passed the Xalan compiling.
I posted code here for other's reference.

From: <Jarno.Elovirta@xxxxxxxxx>
Reply-To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
To: <xsl-list@xxxxxxxxxxxxxxxxxxxxxx>
Subject: RE: how to use the xsl:param in the output html script

Date: Thu, 20 May 2004 09:54:41 +0300

Hi,

>   I want to pass the xsl:param value into the output html
> script function.
>   The Code as follows.
>
>   <xsl:param name="VariableNum" select="count(/Variable)"/>
>   <script>
>     var Variable0 = new Array({$VariableNum});
>   </script>
>
>   It failed.
>   How can I do?
>   Thanks in advance.

The curly braces act as expression delimiters only in Attribute Value

Cheers,

Jarno