   robot.respond /whois oncall/, (msg) ->
     room = msg.message.room
     team = teams[room]
-    return msg.reply "You can only see who is oncall in the following project channels:" + (" <\##{channel}>" for channel, team of teams) if not team
+    return invalidChannel msg unless team
 
     whoIsOncall team, (person) ->
       if person

      error.response = response
      throw error

  lookupUser = (name) ->
    name = name.replace '.', ' ' if name?
    users = robot.brain.users()

    [ __, message ] = msg.match
    room = msg.message.room
    team = teams[room]
    return invalidChannel msg unless team

    whoIsOncall team, (person) ->
      if person
