So for my project in college im making a 'space invaders' type game, but I cant get my tank to move? the code for this is:

Code:
onClipEvent(2){
	if(this._x<=0) this._x=2;
	if(this._x>=580) this._x=478;
	if(this._x>80 && this._x=480;
	if(Key.isDown (Key.RIGHT))
	this._x+=5
}
else if(Key.isDown (Key.LEFT)){
	this._x-=5
}

if(Key.isDown (Key.SPACE))
if(_root.bullet._y>600) {
	bullet._x=this._x
	bulley._y=this._y
}
}
}
but when pressing the left and right arrow keys nothing is happening? Where have I gone wrong in this?

Unless it has something to do with the code on my button on frame one which is

Code:
on(release) {
	gotoAndStop(2)
}
Really stumped with this one!