Collision Question

Ok, its been a while since I have actually tried using wall collisions in a min flash game. So I was just wondering if anyone had any info on what they think was the best way to make walls and collision.
In the past I normaly would just use this._x-=speed; or whatever the opposite of the movement was. But this doesn’t work that well in a situation where you want the collision on both sides of the wall. I could use the getBounds script, but its been awhile since I have used that and can’t remember how it should go. So rather than working it out, first I want to see if anyone else has some more simple or interesting methods.