URLRequests and MovieClips

Question

I'm using AS3.
Is there any chance of creating a function for an instance of an MC to run URLRequests for different items on different frames, or is the only route to create a new MC instance on each necessary frame and type out the request to pull a photo or.swf? Just wondering if I can cut down on the amount of keyframes I'll foreseeably have.
Hopefully that made sense.
Also, how do I run an animated preloader in the movie clip for when it's fetching and loading a photo.
AND, how can I have the photo fade in (guessing somehow through brightness or alpha)? I know there's a lot being asked here. But with my naivete, I'm daunted trying to do these things inside a movie clip.
If any can offer help, thanks, and let me know if I need to provide more context.

Answer 1

oops, my error:
var ldr:Loader = new Loader();
var t:Timer=new Timer(70,0);
t.addEventListener(TimerEvent.TIMER,fadeoutF);
var fadespeed:Number=.03;  // use whatever number suits your needs
function loadAndAddF(mc:MovieClip,urlS:String){
ldr.alpha=0;
var urlR:URLRequest=new URLRequest(urlS);
ldr.load(urlR);
mc.addChild(ldr);
ldr.contentLoaderInfo.addEventListener(Event.COMPLETE,loadCompleteF);
function loadCompleteF(e:Event){
t.start();
function fadeoutF(e:Event){
ldr.alpha+=fadespeed;
if(ldr.alpha>=1){
ldr.alpha=1;
t.stop();
then on each frame where you want to load an image into a frame movieclip use something like:
loadAndAddF(frameMC,"pics/image22.jpg");
// where frameMC is the name of your frame movieclip and you want to load image22.jpg that's in the pics folder.