AI Wall Detection and Object Scope

[icicle]

Hello everyone.

I'm trying to make a platformer with custom movement and collision detection, but I'm having trouble with the collision detection.

Here's what I have so far: Square Unicolor Object Game.mfa

The problem is with events 36 and 37. Basically, I've got AI objects randomly moving left and right. I want them to be stopped when they try to pass through a Ground object, but they're not stopping.
In case you can't or don't want to see the program, here's a sample event:
+Float X (AI) > X (Ground) - 32
+Float X (AI) <= X (Ground) -1
+Float Y (AI) > Y (Ground) -31
+Float Y (AI) < Y (Ground) +31
=> Set Float X (AI) to X (Ground) - 32
Float X and Float Y are alterable values I used to be equivalent to the AI's position coordinates.
I thought this would make any AI objects overlapping any Ground objects from the Ground objects' left sides would be moved directly to the left of the Ground object.

I'm guessing the problem has something to do with object scope, which is something I still don't understand well.

Can anyone clue me in on anything I'm doing wrong here (or shouldn't be doing at all)?
Also, does anyone know some good object scope tutorials for selecting the instances of objects you want?

Thanks,
Icicle

[tompa]

line 37
the ground/platform that Float X is taken from, has no reference

I'd advice to scope by fastloop/spreadvalue until enough aspects are learned, it would be a suitable option for your application.
I think Danny did a tutorial for this.