Splitting a solid body in Two

I have a solid Body and i want to split it into 2 seperate bodies.  I have no problem doing this if I use cut extrude and remove material as it asks which bodies I want to keep.  The thing is I dont want to remove any material and i have been trying to use cut with surface but it dosent give me the option to keep both bodies....

What am I missing?

Thanks in Advance.

Chevis W/

SolidworksGeneral