I was engaged in a similar question.
It is not possible, you must to try a different method.
Read this thread:
http://lists.osgeo.org/pipermail/mapserver-users/2009-January/059537.html
ciao .pg
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Pietro Giannini
Bytewise srl - Area GIS
41°50'38.58"N 12°29'13.39"E
On Mar, Gennaio 27,
I sent this (probably wrongly) to the mapserver-dev list a
couple about a week ago and have not heard back from anyone. So I am
trying my luck here.
I am using PHP MapScript to create a polygon layer based on data stored
in a MySQL database. The layer will show 1x1 degree grid cells and each
cell