ST_Contains with multi polygon

[tabs den]

Hello

I Have 2 type of data : point(car) & Polygons(Boundary of town)
I want to know if my car is in town.

My fonction work well but not when I have MultiPolygons for a Town
When a town has Two or more boundaries my fonction return false even the car is in one Boundary

SELECT name FROM town WHERE ST_Contains(town.geom,GeomFromText( 'Point( $x $y)' ))


Thanks