works for c-script, not sure if it works for lite-c... but you can try

-----------------------------------------

function gravity(){

vec_set(temp, my.x);
temp.z = -999999;
trace_mode = use_box + ignore_me + ignore_passents + ignore_passable;
-trace(my.x, temp);

if(result > 10){my.skill3 -= 150 * time;}
else{my.skill3 = -trace(my.x, temp) * 1;}

//c_move(me, my.skill1, nullvector, glide);

}


hope it helps.