select points out of a polygon

Dear list members

I have a spatial point data frame (spt.points) and a spatial polygon data
frame (spt.poly).

With spt.points[spt.poly,] I can select the points that overlap the polygon.

How can I get the points that do not overlap the polygon?

Thanks a lot.

All the best,

Ant?nio Olinto ?vila da Silva
S?o Paulo, Brasil