public function runMove(dir:String, e:Event):void {
if (dir == "up") {
b4.y = b4.y - 5;
} else if (dir == "down") {
b4.y = b4.y + 5;
} else if (dir == "left") {
b4.x = b4.x - 5;
} else if (dir == "right") {
b4.x = b4.x + 5;
}
}