[Codemonkey]

 
If you are working with Forms (mx.screens.Form), you can use this enhanced version to make your screens smoothly fade in/out when showing/hiding your form:

import mx.transitions.*;
import mx.transitions.easing.*;
 
// use this class on your forms instead
class codemonkey.util.BasicForm extends mx.screens.Form {
    private var __visible:Boolean = false;
    
    public function BasicForm() {
        this.addEventListener("allTransitionsInDone", this);
        this.addEventListener("allTransitionsOutDone", this);
        this.createEmptyMovieClip("bg", this.getNextHighestDepth());
    }
    // display form (show/hide)
    public function show(flag:Boolean) {
        if (flag != this.__visible) {
            this.__visible = flag;
            this.visible = (__visible) ? true : this.visible;
            var fadetype:Number = (flag) ? Transition.IN : Transition.OUT;
            TransitionManager.start(
this, {type:Fade, direction:fadetype, duration:1, easing:None.easeNone}
);
        }
    }
    // called by Flash' transition manager
    private function allTransitionsInDone(eventObj:Object) {
        this.visible = this.__visible;
    }
    private function allTransitionsOutDone(eventObj:Object) {
        this.visible = this.__visible;
    }
} 

To use this class, do as you normally would, but extend from the BasicForm class instead:

class LoadingScreen extends BasicForm {} 

screenshot of applying your form in Flash