Quick question regarding library

programming flash
1

I got this flipbook from iparigrafika which calls symbol from library.

my questions are:

  1. how do we create symbol using as and then its available in library?
  2. if we able to create symbols in library using script, how do we name it?

as far as i know, createEmptyMovieClip do create MC, but its on stage not library right?

i really need help with this. Thx a lot guys