Why are you asking? Conscience got you down?
Now there is an answer to all your problems: moral relativism. After long deliberations, "We" have decided that nobody is able to prove that morality has any meaning, therefore it doesn't have any meaning. This is very convenient as now you don't have to take any responsibility for your actions, and ain't that just swell?
The logic might seem a little unsound to you, it might seem to you that We haven't proven that morality is untrue either. However, do you have any proof that the logic by which you came to that conclusion is true? Didn't think so. In fact, you cannot prove that facts are factual, hahaha. But they sure do hurt. And you don't want to get hurt, do you know?
That's what I thought.