Map Projections

[Ryan Ollerenshaw]

I am having a bit of trouble re-projecting my data.  When I specify the
PROJECTION object in my map file as

PROJECTION
  "proj=cc"
  "lon_0=0"
  "ellps=WGS84"
  "datum=WGS84"
END

Or

PROJECTION
  "proj=cc"
  "lon_0=90"
  "ellps=WGS84"
  "datum=WGS84"
END

My image does not change, but the prime meridian should be changing locations
from the center of the image to the far left.  I also tried to specify the
projection in the layer itself but still no change.  Isn’t MapServer capable of
re-projecting the data regardless of the original projection?