Arrow key movement: change direction

function moveStuff(){
if(Key.isDown(Key.DOWN)){
this._y += 5;
}
if(Key.isDown(Key.UP)){
this._y -= 5;
}
if(Key.isDown(Key.LEFT)){
this._x -= 5;
}
if(Key.isDown(Key.RIGHT)){
this._x += 5;
}
}
lp_mc.onEnterFrame=moveStuff;


thats my basic Arrow key functions to move a movie clip

lp_mc is my character in the left position so when left key is pressed it moves forwards but when right is presssed it moves backwards…

i have a movieclip called rp_mc which is the same thing but facing the other way

when right is pressed how do i swap the lp_mc for rp_mc so it changes direction?