Flash Action Script Key Press Restrictions

Question

Hello, so I am making a Pacman game and am using the following script for the movement of my character.
onClipEvent (enterFrame) {
          speed = 10;
          if (Key.isDown(Key.LEFT))
                    this._x -= speed;
                    _root.char.gotoAndStop(2);
          if (Key.isDown(Key.RIGHT))
                    this._x += speed;
                    _root.char.gotoAndStop(1);
          if (Key.isDown(Key.UP))
                    this._y -= speed;
                    _root.char.gotoAndStop(3);
          if (Key.isDown(Key.DOWN))
                    this._y += speed;
                    _root.char.gotoAndStop(4);
The problem that I'm having is that when I press the right and down keys, or any other two keys that result in diagonal movement, the character moves in that direction.  I only want the character to be able to move right, left, up and down.  The   _root.char.gotoAndStop(3); part of the script is just so that the character faces in that direction.  Is there any way to restrict the number of keys that can be pressed at once to one? Or to make it so that only the first of the two keys or the second of the two keys pressed is used? If not, is there any way to make a RIGHT and DOWN key press result in diagonal movement that also faces the character that way? Or stops the character entirely? I would throuroughly appreciate any help on the matter! Thanks in advance!
Walt

Answer 1

One way would be to incorpate "else" 's for the last three conditionals.  That would make it so that the first key determined to be down would be the key that determines the movement.
onClipEvent (enterFrame) {
          speed = 10;
          if (Key.isDown(Key.LEFT))
                    this._x -= speed;
                    _root.char.gotoAndStop(2);
          } else  if (Key.isDown(Key.RIGHT))          {
                   this._x += speed;
                    _root.char.gotoAndStop(1);
          } else if (Key.isDown(Key.UP))          {
                    this._y -= speed;
                    _root.char.gotoAndStop(3);
          } else if (Key.isDown(Key.DOWN))           {
                    this._y += speed;
                    _root.char.gotoAndStop(4);