ActionScript 3.0 :: Edit A Movie Clip Class In Library?

First off I downloaded the picture and bitmaps for my movie clip class online and it is now part of my library as type movie clip. Then from the library I was allowed to drag it into the stage then name an instance that I could use in my as3 code. This movie clip has some animation, so when the flash is running, the graphic would be "walking" the whole time for example. This class is called "Player"

Then I realized I wanted to encapsulate more of the code in as3, and to do that I wanted to add some methods and variables to this Player class.

I right-clicked the graphic in my stage and I found "edit class". It then brings up a completely empty class definition, strangely named "script1", not even properly named as the class itself.

When I edited it and named it properly and re-compiled, it looks like I basically just re-did a brand new class from scratch as my graphics were completely gone.

At the very least I would expect the Player class to have some linking or loading of my graphic, the starting x/y coordinates (according to how I drag it on the stage), etc.

Why does it bring up a blank class document when I right-click my player? Shouldn't it bring up the code that makes "player" work as I see in the flash? How am i supposed to "append" methods to the already existing class.