Please Help, How to load a movie clip?

programming flash
1

I’m not sure how to ask what I need to do, so I hope this is right. I have a bird that is flying around randomly. If its going forward everything is fine, but if it goes backwards, I’d like to load an image of it in reverse so that it actually looks like its flying in the opposite direction, not flying backwards. But i’m not quite sure how do that. Any help is greatly appreciated. Here is the code I have now to move the bird:

 
onClipEvent (load) { 
//data you may want to change 
width = 640; 
height = 480; 
speed = Math.round(Math.random()*2)+1; 
//initial positions 
x = this._x=Math.random()*width; 
y = this._y=Math.random()*height; 
x_new = Math.random()*width; 
y_new = Math.random()*height; 
} 
onClipEvent (enterFrame) { 
//x movement 
if (x_new>this._x) { 
sign_x = 1; 
} else { 
sign_x = -1;
_rotation = Math.atan2(this.yspeed, this.xspeed)*180/Math.PI;
} 
dx = Math.abs(x_new-this._x); 
if ((dx>speed) || (dx<-speed)) { 
this._x += sign_x*speed; 
} else { 
x_new = Math.random()*width; 
} 
//y movement 
if (y_new>this._y) { 
sign_y = 1; 
} else { 
sign_y = -1; 
} 
dy = Math.abs(y_new-this._y); 
if ((dy>speed) || (dy<-speed)) { 
this._y += sign_y*speed; 
} else { 
y_new = Math.random()*height; 
} 
}

Thanks for any help you might can give me.