Contact structures with distinct Heegaard Floer invariants

We use the Heegaard Floer theory developed by P. Ozsvath and Z. Szabo to give a new proof of a theorem of P. Lisca and G. Matic. In particular, we prove that the contact structures on Y = partial derivativeX induced by non-homotopic Stein structures on the 4-manifold X have distinct Heegaard Floer invariants. Our examples also show that Heegaard Floer homology can distinguish between non-isotopic tight contact structures.