Tile based movement on Actionscript 2.0 (adobe flash cs6) - actionscript-2

Question

So I have got this problem where I do not know how to possible code tile based movement in 4 directions (NSWE) for action script 2.0.
I have this code but it is dynamic movement, which makes the char move in all 8 directions (NW,NE,SW,SE N,S,W,E). The goal is to limit the movements to tile based and in only 4 directions (NSEW)
onClipEvent(enterFrame)
{
speed=5;
if(Key.isDown(Key.RIGHT))
{
this.gotoAndStop(4);
this._x+=speed;
}
if(Key.isDown(Key.LEFT))
{
this.gotoAndStop(3);
this._x-=speed;
}
if(Key.isDown(Key.UP))
{
this.gotoAndStop(1);
this._y-=speed;
}
if(Key.isDown(Key.DOWN))
{
this.gotoAndStop(2);
this._y+=speed;
}
}

Answer 1

The most simple and straightforward way is to move that thing along X-axis OR along Y-axis, only one at a time, not both.
onClipEvent(enterFrame)
{
speed = 5;
dx = 0;
dy = 0;
// Figure out the complete picture of keyboard input.
if (Key.isDown(Key.RIGHT))
{
dx += speed;
}
if (Key.isDown(Key.LEFT))
{
dx -= speed;
}
if (Key.isDown(Key.UP))
{
dy -= speed;
}
if (Key.isDown(Key.DOWN))
{
dy += speed;
}
if (dx != 0)
{
// Move along X-axis if LEFT or RIGHT pressed.
// Ignore if it is none or both of them.
this._x += dx;
if (dx > 0)
{
this.gotoAndStop(4);
}
else
{
this.gotoAndStop(3);
}
}
else if (dy != 0)
{
// Ignore if X-axis motion is already applied.
// Move along Y-axis if UP or DOWN pressed.
// Ignore if it is none or both of them.
this._y += dy;
if (dy > 0)
{
this.gotoAndStop(2);
}
else
{
this.gotoAndStop(1);
}
}
}