How to reference assemblies in the GAC?

I'm trying to figure out how to reference assemblies in the GAC.

I have the following assembly installed in the GAC:

     Dalc, Version=1.0.0.0, Culture=neutral, PublicKeyToken=f71ce40ac4e60391, processorArchitecture=MSIL

I have researched this issue on the web and the solution to this problem appears to be to add the following block to machine.config:

 <system.web>
  <compilation debug="false" explicit="true" defaultLanguage="c#">
   <assemblies>
    <add assembly="Dalc, Version=1.0.0.0, Culture=neutral, PublicKeyToken=f71ce40ac4e60391, processorArchitecture=MSIL" />  
   </assemblies>
  </compilation>
</system.web>

(I have also tried this with Web.config).

I did this and restarted VS2008 but unfortunately wh ...