This file sets the response of the servlets to clear old values from the cashe 
of IE. 
import javax.servlet.http.HttpServletResponse;
public class SessionUtil {
    /**
     * @param args
     */
    public static void setResponse(HttpServletResponse response) {
        try{       
            System.out.println("ENTERING");
            response.setHeader("Cache-Control","no-cache");
            response.setHeader("Cache-Control","no-store");
            response.setHeader("Cache-Control","must-revalidate");
            response.setHeader("Cache-Control","post-check=0");
            response.setHeader("Cache-Control","pre-check=0");
            response.setHeader("Cache-Control","private");
            System.out.println("LEAVING");
        }catch(Exception e){            
            e.printStackTrace();
        }
    }
}