Ifacename$ ()

   Synopsis:
      Returns the name of the active interface that caused 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.
      Returns the name of the active interface corresponding to the trigger,
         alias (etc) that fired. If there is no current notification, returns an
         empty string.
