xslt问题请教!

Question

<?xml version='1.0'?>
   <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:msxsl="urn:schemas-microsoft-com:xslt" xmlns:user="http://mwy" version="1.0">
    <msxsl:script language="Javascript" implements-prefix="user">
<![CDATA[ 
                           function Test(vtest)
                           {
                              var nIndex;
                              nIndex=vtest.IndexOf(".");
                             var strReturn=vtest.substring(1,nIndex+2);
                              return strReturn;  
                            }   
                   ]]> 
</msxsl:script>
    <xsl:template match="/">
<xsl:apply-templates select="/*"/>
</xsl:template>
    <xsl:template match="/*">  
        <table border="0"  CELLSPACING="1" CELLPADDING="0"  nowrap="true" width="100%"  BGCOLOR="#93BEE2" >
<xsl:for-each select="./*">
<tr nowrap="true" align="center" >
   <xsl:for-each select="./*">
     <td align="center" nowrap="true" >
       <xsl:variable name = "A" ><xsl:value-of select ="."/></xsl:variable> 
<xsl:value-of select ="user:Test($A)"></xsl:value-of>
      </td>
        </xsl:for-each>
</tr>
</xsl:for-each>
           
        </table>
    </xsl:template>
    </xsl:stylesheet>
这里的Javascript中为什么不能用substring()函数.请教该用什么办法搞定.