ENTER-ECHO      "echo of a char or a room, when someone enters"

  delay         delay in pulses(*) until the echo might be shown

  dir           (not implemented yet)

  random        do a roll (1 - random), if the result is not 1 the echo will
                not be shown. So the higher the random value, the lower the
                chance that an echo is shown.

  remember      after a character entered(**), do not trigger again for the
                given amount of pulses(*) for just that character

  remember-any  after someone entered(**), do not trigger again for the given
                amount of pulses(*) for any character

  to_char       the echo which is to be sent to the char, who entered

  to_room       the echo which is to be sent to the room (not to the char,
                who triggered the library)
      
  flags         optional flags: (seperated by spaces)

                sunset          only trigger if it is the given daytime
                sunrise                              
                day                                
                night

                noinv           do not trigger, if attached to an obj, which
                                is in someones inventory

                noequip         do not trigger, if attached to an obj, which
                                is worn by someone

                noground        do not trigger, if attached to an obj, which
                                lies on the ground

                nofight         do not trigger, if attached to a mobile,
                                which is fighting

                nomob           do not trigger for entering mobiles


  (*)  20 pulses = 1 second
  (**) someone entered does not nescessarily mean the echo is/was sent