     @workspace.setWatchMode username
     @botReply getMessage "watchReply", username
 
+  replyForStopWatching: ->
+    @workspace.setWatchMode "nobody"
+    @botReply getMessage "watchNobody"
+
   botReply: (message) ->
     messageData =
       message   : message

    invite        : "replyForInvite"
    watch         : "replyForWatch"
    join          : "replyForJoin"

  messages        =
    welcome       : """


  isSystemMessage: (message) ->
    return  unless message
    splitted     = message.trim().split " "
    keyword      = splitted.first
    hasMaxLength = splitted.length is 2
    hasHandler   = replyHandlers[keyword] isnt undefined
    isHelp       = keyword is "help"
    isStopWatch  = keyword is "stop"

    if isHelp
      return splitted.length is 1
    else if isStopWatch
      return message is "stop watching"
    else
      return hasMaxLength and hasHandler

  runSystemMessageHandler: (message) ->
    splitted = message.split " "
