I said it was a bare sketch, you're going to have to fill in some blanks.

In this case, change LibPage to extend MovieClip instead of Sprite, and import flash.display.MovieClip.

Also, I expected you to put the Main code in the timeline. Not because it's better, but because I thought that would seem more intuitive to you. You can put it in a class, but you'll need to put in all the class features like package, class, constructor, and public/private markers