Sweep a sphere open within a solid

hey guys,

i have a rectangular solid, and i want to take out a half sphere out of this solid. So i draw a half circle and try to revolve it 180 degree so it would sweep a half sphere open out of this solid.

but the rectangular solid remains a solid. So the revolving function doesn't do the job. and i want the outer solid shape remains rectangular. so do you have any suggestions?

Thanks

Lee

SolidworksDrawings And Detailing