ActionScript 2.0 :: Have An Enemy Square That Chases The Player Square?

I have this game, and some levels have a moving square as the player, you move the square with your arrow keys.... I want to have an enemy square that chases the player square.... They only chased mario when you didn't look at them? Kinda like that...... but in this regards:

I only want the enemy square to chase the player square when the player square moves.... soo say the player square moves 5 pixels per movement (know how to do all that), I want the enemy square to move when the player square moves..... towards the player square at like 7 pixels per movement..... so eventually you won't be able to avoid the enemy square....