How do I program a character with random motion in the scene, including diagonal movement and exchange of sprites every direction. (AS3).

Were you expecting a code within a main timeline frame? This is a code which should be put within a document's class. That's the most recommended method.

For that to happen, create a new folder, fill it with the FLA file and create a new folder called "classes", where you must have a class file (.as). Call it "Main.as".

Then, open up your FLA file and, with nothing selected, open the properties window. In there, there is a Text Input Field which represents the Class. Write "classes.Main". After doing so, open the library window, where you should have your 4 sprites. Right click one of them and select Properties. A new window will pop up where you should check the "Export to ActionScript" option box. In the Class Text Input Field write "classes.Sprite1". In my previous reply I told you what should be the Sprite1, Sprite2, Sprite3 and Sprite4... Well, this is where you use that formula. In the second Text Input Field (which I don't know how it's written in the English version of the program... maybe Class Base?), write "flash.display.Sprite", and finally, click OK. Do the same thing with each of the other 3 Sprites.

Inside the "Main.as" class file, paste this code:

package classes {

  import flash.display.MovieClip;

  import flash.geom.Rectangle;

  import flash.display.Sprite;

  import flash.display.Graphics;

  import flash.utils.Timer;

  import flash.events.TimerEvent;

  public class Main extends MovieClip {

  public var Enemy: Sprite = new Sprite();

  public var _Sprite1: Sprite1 = new Sprite1();

  public var _Sprite2: Sprite2 = new Sprite2();

  public var _Sprite3: Sprite3 = new Sprite3();

  public var _Sprite4: Sprite4 = new Sprite4();

  public var Sprites: Array = new Array(_Sprite1, _Sprite2, _Sprite3, _Sprite4);

  public var Movements: Array = new Array("Right", "Left", "Up", "Down");

  public var EnemyInicialPosition: Array = new Array(100, 100); // X, Y values

  public var EnemySpeed:Number = 20;

  public var MovementsDelay:int = 500; // Miliseconds

  public var Delay:Timer = new Timer(MovementsDelay);

  public function Main() {

  CreateEnemy();

  RandomMovements();

  Delay.addEventListener(TimerEvent.TIMER, TimerFinished);

  Delay.start();

  }

  public function CreateEnemy() {

  Enemy.x = EnemyInicialPosition[0];

  Enemy.y = EnemyInicialPosition[1];

  stage.addChild(Enemy);

  Enemy.addChild(Sprites[0]);

  for (var i: int = 1; i < Sprites.length; i++) {

  Sprites.visible = false;

  Enemy.addChild(Sprites);

  }

  }

  public function RandomMovements() {

  var IndexNumber:int = Math.floor(Math.random() * (Movements.length));

  var Direction: String = Movements[IndexNumber];

  for (var i: int = 0; i < Sprites.length; i++) {

  Sprites.visible = false;

  }

  if (Direction == "Right") {

  Enemy.x += EnemySpeed;

  Enemy.y += EnemySpeed;

  Sprites[IndexNumber].visible = true;

  }

  if (Direction == "Left") {

  Enemy.x -= EnemySpeed;

  Enemy.y -= EnemySpeed;

  Sprites[IndexNumber].visible = true;

  }

  if (Direction == "Up") {

  Enemy.x += EnemySpeed;

  Enemy.y -= EnemySpeed;

  Sprites[IndexNumber].visible = true;

  }

  if (Direction == "Down") {

  Enemy.x -= EnemySpeed;

  Enemy.y += EnemySpeed;

  Sprites[IndexNumber].visible = true;

  }

  }

  private function TimerFinished (e:TimerEvent) {

  RandomMovements();

  }

  }

}