Tracking Missile Won't Hit Ship

I have a missile. When I press a button, a missile is launched. The missile then proceeds to hit a ship. The ship is moving to the right. The missile misses the ship to it's left, sorta like the earth/cannon-ball model. How do I get a missile to hit a ship every single time?
Comments
Intact and ANGRY....
Any help?
QS
Another thing...
maybe you can subtract some number from ships position X. So the missile will move farther to left. (or + to the right)
ex: Accelerate Towards Position: game.EnemyPositionX -20
Not sure if this is what you mean