A ladder system that works
2. object player
if player overlays ladder
-> Platform disbled
on key pressed Up -> Set player.animation to "climb"
player.y = y+1 (or whatever you want)
on key pressed down -> same theory as above
Now to "dismount"
find out x,y of locations where you want to exit
player.y > location.y -> platform enabled
player.animation = "default"
The above MAY work, i did not test it since i do not have construct at hand right now.. if no one posts any solution until i'm home i may post a working example.