Calculate the power

HI there, this is my program. I'm trying to calculate the power of a number entered first but when i click on the button, nothing happens.

Helps pls.

Tks a lot.

package

{

                import flash.events.*;

                import flash.display.*;

                import flash.text.*;

                public class U1A7_Puissances extends MovieClip

                {

                               public var entierBase:TextField;

                               public var entierExposant:TextField;

                               public var btnCalculer:SimpleButton;

                               private var maMiseEnForme:TextFormat=new TextFormat();

                               private var afficheReponse:TextField=new TextField();

                               public function U1A7_Puissances()

                               {

                                               this.btnCalculer.addEventListener(MouseEvent.CLICK, this.calculPuissance);

                               }

                               private function calculPuissance(event:MouseEvent):void

                               {

                                                               var intBase:int = 0;

                                                               var intExposant:int = 0;

                                                               var nouvMessage:String= "";

                                                               var i:int=0;

                                                               intBase = int(this.entierBase.text);

                                                               intExposant = int(this.entierExposant.text);

                                                               while (i++ < intExposant)

                                                               {

                                                                              nouvMessage=(nouvMessage + intBase + " exposant " + i + " = " + Math.pow(intBase,i) + "\n");

                                                               }

                                               maMiseEnForme.font="Arial";

                                               maMiseEnForme.size=20;

                                               maMiseEnForme.color=0x0000FF;

                                               afficheReponse.defaultTextFormat=maMiseEnForme;

                                               afficheReponse.x=50;

                                               afficheReponse.y=50;

                                               afficheReponse.border=true;

                                               afficheReponse.borderColor=0x000000;

                                               afficheReponse.autoSize=TextFieldAutoSize.LEFT;

                                               afficheReponse.text = nouvMessage ;

                                               addChild(maReponse);

                               }

                }

}