Projection/Extent help

[Camden Daily]

Hello all.  I'm a mapserver newbie trying to figure something out.
Basically, I have two sets of shapefiles in different projections and
units.  One has units of dd, and one has units of feet.

When I combine the two, I'd like to define my extents for the whole
.map file using dd instead of feet.  I've made up a sample .map file
where I'm simply trying to display one layer with units of feet while
defining the extent using dd.  However, everything I try just gives me
a blank page.

If I define the extent in terms of feet and drop the "proj=latlong"
line, it shows up fine.  But I just can't get it to work when I define
the extent in dd.

Any help would be much appreciated!
-Camden Daily

MAP

  NAME Chicago
  STATUS ON
  DEBUG ON
  SIZE 300 300
  IMAGETYPE PNG
  IMAGECOLOR 240 240 240
  SHAPEPATH "/web_system/data"
  FONTSET "/web_system/fonts/fonts.list"
--------
  EXTENT -87.74 41.80 -87.56 41.98
  UNITS DD
  PROJECTION
    "proj=latlong"
  END
-------
  #EXTENT 1101584.450000 1841973.900000 1186739.850000 1969991.020000
  #UNITS FEET
-------
  WEB
    LOG "/web_system/logs/mapserver.log"
    IMAGEPATH "/web_system/tmp/"
    IMAGEURL "/tmp/"
  END

  LAYER
    NAME "cta_line"
    TYPE LINE
    STATUS DEFAULT
    DEBUG ON
    DATA "CTA_Line"
    CLASS
      COLOR 0 0 0
    END
    PROJECTION
       "init=epsg:26971"
    END
    UNITS FEET
  END

END