This code show how to create snowfall in flash cs4

u can also use the code for cs3

package {

	import flash.display.MovieClip;
	import flash.events.Event;
	import flash.filters.BlurFilter;
	import druva.NumberUtil;
	import flash.utils.Timer;
	import flash.events.*;

	public class snowfall extends MovieClip {

		private var t:Timer;

		public function snowfall():void {
			t=new Timer(80);
			t.addEventListener(TimerEvent.TIMER, createParticle);
			t.start();
		}

		private function createParticle(e:TimerEvent) {

			var mc_particle:MovieClip =new MovieClip();
			mc_particle.graphics.beginFill(0xFFFFFF,1);
			mc_particle.graphics.drawCircle(0, 0, NumberUtil.getRand(3,5));
			mc_particle.graphics.endFill();

			mc_particle.x=NumberUtil.getRand(-60,600);
			mc_particle.wind = (NumberUtil.getRand(0,1) == 1) ?  'left' : 'right';
			mc_particle.filters=[new BlurFilter(10,10,2)];
			mc_particle.addEventListener(Event.ENTER_FRAME, moveParticle);
			addChild(mc_particle);

		}

		function moveParticle(e:Event):void {
			var targ:MovieClip=MovieClip(e.target);

			if (targ.y>400) {
				targ.removeEventListener(Event.ENTER_FRAME,moveParticle);
				removeChild(targ);
				return;
			}

			targ.y += 1;

			if (targ.wind=='left') {
				targ.x += 0.4;
			} else if (targ.wind== 'right') {
				targ.x -= 0.4;

			}

		}

	}
}

var gradientColors:Array = [0xFF00FF,0x33CCCC];
var gradientAlphas:Array = [1,1];
var gradientRatios:Array = [0,255];

var matrix:Matrix = new Matrix();
matrix.createGradientBox(120, 120, 45);
graphics.beginGradientFill(GradientType.RADIAL, gradientColors, gradientAlphas, gradientRatios, matrix);
graphics.drawCircle(60, 60, 60);

var circle:Shape = new Shape();
addChild(circle);
circle.x = circle.y = 150;
circle.graphics.lineStyle(40);

var gradientColors:Array =
	[
		 0xFF0000,
		 0xFFFF00,
		 0xFF00FF,
		 0xFF6600,
		 0x00FFFF,
		 0x2E0854,
		 0x8F5E00,
		 0x8F5E99,
		 0xFFFF00,
		 0xFF00FF,
		 0xFF6600
	];
var gradientAlphas:Array = [1,1,1,1,1,1,1,1,1,1,1];
var gradientRatios:Array = [0,25,50,75,100,125,150,175,200,225,250];

circle.graphics.lineGradientStyle(GradientType.LINEAR, gradientColors, gradientAlphas, gradientRatios);

circle.graphics.drawCircle(-10, -10, 100);         

import flash.display.*;

var red:ContextMenuItem = new ContextMenuItem("red");
var green:ContextMenuItem = new ContextMenuItem("green");

red.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT, red_Select);
green.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT, green_Select);

var contextmenu:ContextMenu = new ContextMenu();

contextmenu.customItems.push(green);
contextmenu.customItems.push(red);
contextmenu.hideBuiltInItems();

var sprite:Sprite = new Sprite();

sprite.contextMenu = contextmenu;
sprite.graphics.beginFill(0x0000FF);
sprite.graphics.drawCircle(60, 30, 20);
addChild(sprite);

function green_Select(evt:ContextMenuEvent):void {
    sprite.graphics.beginFill(0x00FF00);
    sprite.graphics.drawCircle(60, 30, 20);
}
function red_Select(evt:ContextMenuEvent):void {
    sprite.graphics.beginFill(0xFF0000);
    sprite.graphics.drawCircle(60, 30, 20);
}

(more…)

package druva {

 import flash.display.*;

 public class drawCircle extends Sprite {

 public function drawCircle() {
 var canvas:Shape = new Shape(  );
 canvas.graphics.lineStyle(3, 0xFF0000);
 canvas.graphics.drawCircle(100,100,50);
 addChild(canvas);

 }
 }
}