pro·ac·tive \prō-ˈak-tiv\
adj.
*Action and result oriented behavior, instead of the one that waits for things to happen and then tries to adjust (react) to them. (Merriam-Webster Dictionary)
*Tending to initiate change rather than reacting to events. (The Free Dictionary)
*(of a person, policy, or action) creating or controlling a situation by causing something to happen rather than responding to it after it has happened. (Oxford American Dictionary)