[UMN_MAPSERVER-USERS] How can I label a Point using different postgis table

[Luis Treviño Huerta]

Hi list:

I'm currenttly using a point layer that displays some GPS points that are 
stored on a postgis table called "loca". I'd like to label this points with 
data that comes from another table in the same postgis data base (this table 
is named "autos"), both tables share a common column named "idunit" and I 
would like to use autos.idunit as a label. How can I do this?. This is part 
of my map file:

LAYER
  NAME gis
  STATUS ON
  TYPE POINT
  UNITS METERS

  DEBUG ON
  CONNECTION "user=XXX password=XXXXX dbname=bsiubica host=XXX.XXX.XXX.XX 
port=5432"
  CONNECTIONTYPE postgis
  DATA "posicion from loca as foo using unique cmpoid using srid=4326"

  PROJECTION
     "proj=longlat"
     "ellps=WGS84"
    "datum=WGS84"
  END

 FILTER 'idunit = %unid%'

  CLASS
    EXPRESSION ('[mo]' = '1')
    COLOR 255 255 26  #amarillo
    SYMBOL 7
    SIZE 13
  END
END

regards,
Luis