[Help]Movement using the keyboard(How to flip)

Hi
Im working on a game right now and have a problem: I want to move the “character” with the left and right keyboard buttons
Here is the AS I found on the tutorial:
[AS]on (keyPress “<Left>”) {
currentX = this._x;
this._x = currentX - 2;
_root.man._rotation = ;
}
on (keyPress “<Right>”) {
currentX = this._x;
this._x = currentX + 2;
_root.man._rotation = ;
}[/AS]

The problem is i dont wanna rotate the pic. I just wanna flip it horizontaly whenever i press the left or right button. Is there a way to do that??

thank you verry much