Colision Detection AS2.0 Ball rebound Help NEW

Ok not really part 2 but it seems like it to me because my part one wasnt relly able to be answered fully. So I am going to pose a new and improved question. I have a animation of a golf ball that needs to rebound off the lvl walls but the lvl walls are irregulare shapes so it is a little more tricky then usual. so, since the usual

if (this._x > 400)
{
this.dx *= -1;
}
if (this._x < 10)
{
this.dx *= -1;
}
if (this._y > 300)
{
this.dy *= -1;
}
if (this._y < 10)
{
this.dy *= -1;
}

will not work since the boundrie is not a box, would it be posible to test the left right top and bottom hitTest for the ball bouncing be cause if it can then maby i can figure out how to get this dang ball to rebound so that its angle changes and make it stop coming back to were it was hit from in the first place.