Classic ASP, Application state variable value not same for different users when in StateServer mode

Question

My application is a mixture of asp classic and asp.net pages. In web.config sessionState mode is StateServer, because I allowed multiple threads in IIS. So when I try to access the application from different browsers\machines the value in Application state variable is different for every browser. Am I missing any setting in web.config?

      Application.Lock(); 
      var sessionId = Session.SessionID; 
      var sessionIDACC = new String(Application("SessionIDACC"));
      if (sessionIDACC == undefined || sessionIDACC == 'undefined')
      {             
         Application("SessionIDACC") = sessionId; 
         sessionIDACC = new String(Application("SessionIDACC"));   
         Response.Write("Added by : " + sessionId);
      } 
     else 
     { 
         if (sessionId != sessionIDACC) 
             Response.Write("Application is locked by : " + sessionIDACC);
         else 
             Response.Write("You are using it! your id is : " + sessionIDACC); 
        }
     Application.Unlock();