Canon Dslr Lenses Will Sigma Slr Lenses Work With A New Canon Dslr?

Will sigma slr lenses work with a new canon dslr? - canon dslr lenses

I have a Sigma SA-7N SLR and 28-80mm and 70-300mm lens. I want to buy a Canon EOS Rebel T1i. I would like to know if the lens is already working with this new digital SLR camera, or should I purchase a new lens ..