Ifacetext$ ()

   Synopsis:
      Returns the cause of the the current interface notification

   Notes:
      The interface notification list contains all the notifications received,
         and not yet processed, as the result of an earlier SETTRIG, SETALIAS,
         SETMACRO, SETTIMER or SETHOOK statement.

      This function works in a different way, depending on the type of
         interface that generated the notification.

      After a SETTRIG statement, returns the line of text received from the
         world that caused the trigger to fire.
      After a SETALIAS statement, returns the world command that caused the
         alias to fire.
      After a SETMACRO statement, returns the keycode string that caused the
         macro to fire. (A keycode string consists of one or more keycodes
         combined in a single string; if there is more than one keycode,
         successive keycodes are separated by a space character).
      After a SETTIMER statement, returns the time at which the timer fired (an
         epoch time, measured in seconds). The value is returned as a string.
      After a SETHOOK statement, returns the hook event that caused the hook to
         fire.

      The Ifacetext$ () function is often used together with the Ifacedata$ ()
         function, which returns more information about what caused the
         interface to fire. (The extra information is especially useful for
         aliases, macros and hooks).
