Questions for starter

hi i m new here and i just started learning flash-actionscript
Qs:
1)how can i use something as a backround (for example the tutorial with the snow http://www.kirupa.com/developer/flash8/snow.htm)
2)what s the difference when i write on different actions levels?
3)does anybody know where i can find an actionscript code for the tetris game???
please help me…!!! i m totally confused