The Dink Network

Yes, the script is ok, but I think it's useless, because you can check for other monsters on the screen in a monster's die procedure. When a monster dies, if there aren't any other monsters, unlock the screen(check some monsters scripts from the source).
Anyway, if for some reasons you'll use this script, add
sp_nohit(&current_sprite,1);
after
sp_nodraw(&current_sprite,1);
or dink will be able to punch an invisible thing.