I want to show that any orientation preserving self-homeomorphism of a 2-sphere $S^2$ is isotopic to identity.
Any help or reference is appreciated.
Edit; I want to show this to prove the following. Suppose we have two solid torus and we have a homeomorphism of the boundaries. The manifold obtained by indentifying boundaries via the homeomorphism depends only on the image of the meridian. To show this, first cut out the cylinder neighborhood of a meridian and glue it to the other solid torus. The reminder is homeomorphic to $B^3$. So if I can prove the question above, I can finish this proof.