i would really appreciate it if someone could give me a more in depth explanation of how this tutoiral works:

http://www.kirupa.com/developer/mx2004/snow.htm

i understand the ideas behind the script and what you are asking flash to do. the thing is my maths isnt that great. if someone could explain how some of the equations work, that would be excellent

examples:

this._alpha = 20+Math.random()*50; [color=#ff0000]ok, randomising alpha. got it. but where do these numbers come from? how did you reach them?[/color]

or

// horizontal movement

rad += (k/180)*Math.PI;

xmovement = _root._xmouse;

this._x -= Math.cos(rad)+(xmovement-(width/2))/50;

[color=red]understand what this is trying to do here. butâ€¦ manâ€¦ the maths goes right over the top of my headâ€¦ and explanation??[/color]

[color=black]thanks very much in advance!! ;)[/color]

-hazza