  We establish surgery formulas for filtration of the Heegaard Floer homology
associated with p/q surgery on a null-homologous knot K in a three-manifold Y,
induced by K_{p/q}. Here K_{p/q} is the core of the attached solid torus (which
produces the surgery). This would generalize a result of Ozsvath and Szabo. We
will re-prove that surgery on non-trivial knots can not produce S^3, as a
corollary of a non-vanishing result for the knot Floer homology of K_{p/q}.
