XML : I can't use a param in this XML select statement

I have this XSLT1.0 code:

  

I have now changed my method to have a param called Class. So I wanted to do:

              <xsl:value-of select="//Labels/CounselPoint"/>&#160;<xsl:value-of select="StudentTalk1{$Class}/@StudyPoint"/>&#160;    

Visual Studio does not like it. How do I use a param in my statement?