Offset a line?

[Pete Deffendol]

I'm trying to draw a line layer such that it is offset some amount of 
pixels from its actual location.  The intent is to draw a dashed line 
next to (not atop) a road.  From the documentation, it appears that 
using OFFSET in the STYLE block will work, but it's not having any 
affect on the output.  Here's the relevant section of my mapfile:

LAYER
...
STATUS       ON
  TYPE         LINE
  SIZEUNITS    PIXELS

...
 
    CLASS
      ...
      STYLE
        COLOR 255 128 0
        WIDTH 2
        OFFSET 8 -99
      END
    END
END

I'm going by some documentation at 
http://mapserver.gis.umn.edu/docs/howto/cartosymbols/#construction-of-line-symbols

Am I doing something wrong here?  Or is this even possible?

I'm using Mapserver 5.0 beta 6, through PHP Mapscript.

Pete

-- 
Pete Deffendol
Software Engineer
Multimedia Data Services Corp.
pete at mdsc.com