NAME:
  eggtimer
 PURPOSE:   (one line only)
  Widget countdown timer
 DESCRIPTION:
 This program is a non-blocking widget that will count down from a
   user modifiable duration.  You can run more than one of these at the
   same time.  Once the time has counted down to zero, the color changes to
   red and it starts counting up from the time that the timer expired.
 CATEGORY:
  Widgets
 CALLING SEQUENCE:
  eggtimer
 INPUTS:
 OPTIONAL INPUT PARAMETERS:
  ALERTCMD - Optional string that will be executed by the "spawn" command
               when the timer expires.  This can be used to run a program,
               send mail, play a sound, pretty much anything that you want.
               The default is to not do anything special.
 KEYWORD INPUT PARAMETERS:
 OUTPUTS:
 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  Written by Marc W. Buie, Lowell Observatory, 2005/05/06