How do I not render the white background when displing NEXRAD from a WMS

[Andrew Parker]

Ok.  I give up.  How do I NOT render the white background?  I just want the
base reflectivity to show.  I am accessing a base reflectivity layer from a
WMS located at:

"http://mesonet.agron.iastate.edu/cgi-bin/wms/nexrad/n0r.cgi?"

My test site is available for viewing at:  "http://mapserver.rthicksconsult.com"

There are two test sites.  1) the form button "Click Here..."; my first map.
                                     2) Link: Test1;  my first Chamelon map.

Both have the NexRad Layer as shown below in the partial mapfile.

Thanks in advance.

Andrew.

#
# Start of map file
#
# Sample map file for a chameleon app.
#
NAME DEMO
STATUS ON
SIZE 400 300
SYMBOLSET ../etc/symbols.sym
EXTENT -109.1 31.26 -102.89 37.09
UNITS DD
PROJECTION
  "init=epsg:4326"
END
SHAPEPATH "../data"
IMAGECOLOR 25 25 112
FONTSET ../etc/fonts.txt
TRANSPARENT TRUE
# IMAGETYPE - set to PNG24 in /congif/chameleon.xml

...
...
...

# ******************** NexRad********************
LAYER
  NAME "Nexrad"
  STATUS ON
  TYPE RASTER
  CONNECTIONTYPE WMS
  CONNECTION "http://mesonet.agron.iastate.edu/cgi-bin/wms/nexrad/n0r.cgi?"
  PROJECTION
    "init=epsg:4326"
  END
  METADATA
    "wms_name" "nexrad-n0r"
    "wms_server_version" "1.1.1"
    "wms_srs" "EPSG:4326"
    "wms_format" "image/jpeg"
    "wms_title" "NEXRAD BASE REFLECT"
  END
END

END # end of mapfile