ok please dont flame me i dont know AS (only like 2 lines..)

1. how do use the built in preloader it never works for me tutorial would be nice

2. im working on a game were an alien thing walks across the screen u shoot it and it turns around and goes in opposite direction i dont know what as lines to use

3. sound ive made a button on but how would i make it so when u press it a random sound fx plays (out of about 15)

thnx