Ehh it's good start, but it needs some adjustments. If you haven't already try RAYCASTER.LIB, it can be found in the files of Spooky Maze, which you can find on smile basic source
As you might already perceive, your maze is a little bit distorted.
I guess one of the causes of this distortion is that you have magnify corns dissimilarly. (width/height ratio isn't constant)
Unfortunately I have not hit upon a solution yet.