Dynamic positioning!

Th pictures are the same it’s just for testing.
here’s the code on the onEnterFrame of my pic container :


container_mc.onEnterFrame=function(){
 
	 //PRELOADING
	 charge=this.container.getBytesLoaded()
	 total=this.container.getBytesTotal()
	 rapport=Math.round((charge*100)/total);
	 if(charge==total){
	 this.preloader._visible=false;
	 this.preloader.barre._xscale=0; 
 
	 //CENTERING THE PICTURE	 
	 largeur=(this._width/2)-(this.container._width/2);
	 hauteur=(this._height/2)-(this.container._height/2);	 
	 this.container._x=largeur;
	 this.container._y=hauteur;
	 this.container._visible=true;
 
	 }else{
	 this.preloader.barre._xscale=rapport;
	 trace(this.preloader.barre._xscale);
	 this.container._visible=false;
	 this.preloader._visible=true;	 
	 }
 
	 //FADEIN 
	 this.container._alpha+=5;
	 if(this.container._alpha>=100){
	 this.container._alpha=100;
	 trace(this.container._alpha);
	 delete this.onEnterFrame;
	 }
	 };