# File locana/l_scrollbar.rb, line 656
   def on_mouse_lup(levent=nil, &block)
      return bind(:on_mouse_ldn, block) if (block) # this necessary to support Blocks the same as Proc objects

      @@l_button_dn_timer.cancel()
      @@l_button_dn_timer_delay = LEFT_BUTTON_DOWN_START_REPEATING
   end