# File lib/ajaxim.rb, line 194
  def leaveroom(room)
    # checks if room name contains invalid symbols or empty
    return 'invalid_chars' if (room != room.sanitize_alphanum() || room.nil? || room.empty?)
    #
    sql = "SELECT id FROM {ajaxim_chats} WHERE uid = '" + @user["uid"] + "' AND room = '" + room + "'"
    res = @db.query(sql)
    
    if res.num_rows > 0 
      # writing to log user leaveroom event
      @@logger.room_event(@user['name'], room, 'Left room') if @logging == true
      
      room_info = res.fetch_hash
      # leave room
      sql = "DELETE FROM {ajaxim_chats} WHERE id = '" + room_info["id"] + "'"
      @db.query(sql)
      #
      # notify chatmates about user's leaving
      sql = "SELECT a.uid, u.name FROM {ajaxim_chats} a 
             LEFT JOIN {users} u ON u.uid = a.uid 
             WHERE a.room = '" + room + "'"
      res = @db.query(sql)
      output = {'users' => Array.new}
      res.each_hash do |user|
        output['users'].push(user["name"])
      end
      notify_buddies = user_event(output, "chat,left,#{room}");

      'left'
    end
  end