Flash Chaching for Images

Question

I am trying to preload images that are used throughout a
flash slideshow. I have a preloader that takes an array of
filenames (imageArray) and uses that to load an image into a movie
clip. Each movie clip has an image, all movie clip images are held
within one other movieclip.
So...
holder_mc.mc0 has an imageArray[0]
holder_mc.mc1 has an imageArray[1]
holder_mc.mc2 has an imageArray[2]
...and so on.
They load fine into these movie clips, but now I need to know
how I can use these movie clips in another movie clip in the
animation part.
Right now I am just loading the image into the movie clip,
hoping that the image is cached somewhere in flash and it
automatically pulls it from there instead of download it again. Is
that how it works or not?
What I'm diong now:
main_mc.loadMovie(imageArray[0]);
then later:
main_mc.loadMovie(imageArray[1]);
etc...
Is this just redownloading the image? Or is it getting it
from a cache? If it isn't getting it from cache, how can I use the
stored images in the holder_mc clip to load into the main_mc clip
when I need them?

Answer 1

no, it's not necessary (nor particularly efficient).
yes, you can download them sequentially into the same target
movieclip.
yes, after intially retrieving the image from a server the
image is thereafter retrieved from the user's cache (unless you do
something to prevent that).
and no, the images don't need to exist within flash for
retrievals after the first to be made from the cache.