code: public final void login()
      {
          final IRequestParameters paras = RequestCycle.get().getRequest().getRequestParameters();
          final StringValue name = paras.getParameterValue("name");
          final StringValue pwd = paras.getParameterValue("password");
          if (checkLogin(name.toString(), pwd.toString())) {
              this.userName = name.toString();
              // on login a valid Context for the User must be opened to ensure that the
              // session attributes that depend on the user are set correctly before any
              // further requests are made (e.g. setting the current company
              openContext();
              setAttribute(EFapsSession.LOGIN_ATTRIBUTE_NAME, this.userName);
              RegistryManager.registerUserSession(this.userName, getId());
          } else {
              this.userName = null;
              this.sessionAttributes.clear();
          }
      }
docs: Method to log a user with the Parameters from the Request in.
  
  @see #checkLogin(String, String)