buffer function in php/mapscript

[Stathis Stergou]

Dear list,

I'm new to mapserver and all of its concepts, so please forgive any
mistakes. I would like to develop an application using php/mapscript. Basic
demand for this application is : the user must select features from an
existing layer using a spatial query e.g. "find the all the buildings that
are 100 meters away from a street (or any other shape)", the user must have
the ability to add or remove features to the current selection using a
spatial or a non spatial query e.g. "from all these buildings select only
those which are more than 10 meters high". Is it possible to do this ?

Do i have to use postgis?

I have read that mapserver 4.6 uses geos library, but i cannot find any
documentation about the new function made available in php/mapscript.
Thanks in advance.

Stathis Stergou