Interesting chase/follow command

Hey there,

I am in the process of creating a kind of cat and mouse style game but the player controls a car and a police car chases and you are timed to see how long you last before your car loses its life from too many collisions…

I found an awesome site http://www.sploder.com/free-game-creator.php that lets you create your own game. Within this, There are wingman that follow you around but don’t get stuck and have a bit more intelligence than my police car! I have already written some code but I am having some trouble with the police car as it keeps getting stuck behind buildings. Could you tell me where i am going wrong? Or point me in the direction of a decent tutorial?

At the moment I’ve been working with this for the police car:

if (this._x<_root.player._x or this._x<_root.player._x+1) {
this._x += 2;
} else {
this._x -= 2;
}
if (this._y<_root.player._y or this._y<_root.player._y+1) {
this._y += 2;
} else {
this._y -= 2;
}

Thank you for you time and help