Why my player cant hit the higher ground?

Feel wanna throw something already...
why my player cant hit the higher ground?
my code is something like this:

if(ground_mc.hitTest(player_mc._x, player_mc._y, true)){
trace("Congratulation! You are standing in the right place...");
}

in my case, player only can stand at the ground...huhuhu...

??????
cant try use normal hit test?
if(ground_mc.hitTest(mc_player))
{
...
}

STILL CANT!!!!!

hmmm...
suppose to work properly...
at last, mine can hit the enemies..HAHAHA ^^