How to add object collision to this wall?

I made this code : but i cant get the object collision to work… i searched on alot of forums, youtube, etc and still cant find it… So could someone help me here?

Thanks already! :stuck_out_tongue:

What do you mean by object collision? I don’t see any other objects other than the main character.

The black bar at the left top side! It could be hard to see but its there