Morf from one pic to next?

1

Hello. How would you morf from one picture to the next when loading it through xml and .load?

currently I have the pictures just fading, but before it fades to the next picture it fades from a blank screen and not from the previous picture that was displayed.

This is the code I have currently:


switch (buttonWanted) {
   case "b1" :
         imageLoader.load(new URLRequest (subImageArray [Number(e.currentTarget.name)-1]));
         TweenLite.from(imageHolder, 1.5, {alpha:0});
         break;

     case "b2" :
         imageLoader.load(new URLRequest (subImageArray [Number(e.currentTarget.name)-1]));
         TweenLite.from(imageHolder, 1.5, {alpha:0});
         break;
//etc for a total of 4 btns

thanks for any help!