I am extremly confused by your code. try this:
const gravity#=-.2
;Collisions
Const TYPE_PLAYER=1,TYPE_CAMERA=2,TYPE_SCENERY=3
; Player-to-scenery
Collisions TYPE_PLAYER,TYPE_SCENERY,2,3
hero\y_vel#=hero\y_vel#+gravity#
hero\y=hero\y+hero\y_vel
translateentity hero\entity,0,hero\y_vel,0
note: this might be wrong as I did it in the browser :-/ also, it assumes that you have a y_vel field in type hero.
const gravity#=-.2
;Collisions
Const TYPE_PLAYER=1,TYPE_CAMERA=2,TYPE_SCENERY=3
; Player-to-scenery
Collisions TYPE_PLAYER,TYPE_SCENERY,2,3
hero\y_vel#=hero\y_vel#+gravity#
hero\y=hero\y+hero\y_vel
translateentity hero\entity,0,hero\y_vel,0
note: this might be wrong as I did it in the browser :-/ also, it assumes that you have a y_vel field in type hero.