AS3 preoloader - code overload

Is there an easier way to create a custom preloader animation in AS3? The
only information I can find on the web tends to have about two pages of code
with stuff like "packages" and "public/private functions" which I've never
used and unfortunately do not understand. The idea seems simple to me [(var
ratio = (bytesLoaded/bytesTotal)*100) then have a movie clip (load_mc) one
hundred frames long displaying 00-99 respectively for each frame. Then find
some way to call a function that says [load_mc.gotoAndStop(ratio);]. I've
seen AS2 tutorials on this subject and they all kinda follow this general
idea. Why then in AS3 do you need two pages of code for an action that
required 5 or 6 lines of code in a previous version of ActionScript (AS2)?
No..no...sorry that's not my question. **sighs** I just need to know if
there is an easier-to-understand method to creating prealoaders in AS3? I'm
making an intro movie for a new website and the final swiff will probably be
close to 1 MB so I want to display a simple loading animation instead of a
blank screen. Any help is greatly appreciated.