If the President doesn't want to deal with a bill and lets it sit for TEN days while Congress is in session, it automatically become law.
A law passed by a simple majority in both houses of Congress is enacted, or acquires the force of law, in one of the following ways:
-Signature of the President of the United States.
-Not being subject to a presidential veto in the next ten days (Sundays excluded), while the Congress is in session.
-Reconsideration by Congress after a presidential veto during its session, with a 2/3 majority in both houses.