NAME:
  matchup
 PURPOSE:
  Read a batch of FITS files and create a list of common object exposures.
 DESCRIPTION:

 CATEGORY:
  Astrometry
 CALLING SEQUENCE:
  matchup,root
 INPUTS:
  root - String, root of file name for the FITS files.
 OPTIONAL INPUT PARAMETERS:

 KEYWORD INPUT PARAMETERS:
  OUTFILE - Name of output match file, default = root+'.match'
  PATH - Path of where to find the source images, default=current directory.
  PATTERN - File searching pattern, default='.???'
  OBJECTKEY - Name of FITS keyword to use for the object name (default=OBJECT)
 OUTPUTS:

 KEYWORD OUTPUT PARAMETERS:

 COMMON BLOCKS:

 SIDE EFFECTS:

 RESTRICTIONS:

 PROCEDURE:

 MODIFICATION HISTORY:
  98/06/23, Written by Marc W. Buie, Lowell Observatory
  99/04/25 - MWB, Removed spawn call to make it work under Windows
  99/06/10, MWB, added pattern keyword
  2000/02/05, MWB, Added support for '.fits' tag on file names.
  2001/05/16, MWB, added OBJECTKEY keyword
  2004/9/21, MWB, removed obsolete call to Findfile