อยากทราบวิธีเขียน action script ให้รถชนกันครับ คือว่าผมอยากรู้การทำให้รถชนกันน่ะครับ คือตอนนี้ผมวาดรถสองคันให้วิ่งสวนกัน

car_mc.stun = 0;
car_mc.speed = 0;
car_mc.acc = 1.700000E+000;
car_mc.maxSpeed = 10;
car_mc.spin = 0;
car_mc.maxSpin = 10;
car_mc.handling = 1.300000E+000;
car_mc.onEnterFrame = function ()
{
    with (this)
    {
        if (Math.abs(speed) > 1.000000E-001)
        {
            speed = speed * 9.000000E-001;
        }
        else
        {
            speed = 0;
        } // end else if
        if (Math.abs(spin) > 1.000000E-001)
        {
            spin = spin * 8.500000E-001;
        }
        else
        {
            spin = 0;
        } // end else if
        if (Math.abs(speed) > maxSpeed)
        {
            speed = speed * 9.000000E-001;
        } // end if
        if (Math.abs(spin) > maxSpin)
        {
            spin = spin * 8.500000E-001;
        } // end if
        if (stun <= 0)
        {
            if (left_mc.hitTest(_root.wall_mc) || right_mc.hitTest(_root.wall_mc))
            {
                speed = speed * -7.000000E-001;
                stun = 20;
                if (left_mc.hitTest(_root.wall_mc) ^ right_mc.hitTest(_root.wall_mc))
                {
                    if (left_mc.hitTest(_root.wall_mc))
                    {
                        spin = spin + 4;
                    }
                    else
                    {
                        spin = spin - 4;
                    } // end if
                } // end if
            } // end else if
            if (Key.isDown(38))
            {
                speed = speed + acc;
            }
            else if (Key.isDown(40))
            {
                speed = speed - acc;
            } // end else if
            if (Key.isDown(37))
            {
                spin = spin - handling;
            }
            else if (Key.isDown(39))
            {
                spin = spin + handling;
            } // end else if
        }
        else
        {
            --stun;
        } // end else if
        if (Math.abs(speed) >= 3)
        {
            _rotation = _rotation + spin;
        }
        else
        {
            _rotation = _rotation + spin * Math.abs(speed) * 2.000000E-001;
        } // end else if
        _y = _y + speed * Math.sin(_rotation * 3.141593E+000 / 180);
        _x = _x + speed * Math.cos(_rotation * 3.141593E+000 / 180);
        if (_x > 500)
        {
            _x = -100;
        }
        else if (_x < -100)
        {
            _x = 500;
        } // end else if
        if (_y > 400)
        {
            _y = -100;
        }
        else if (_y < -100)
        {
            _y = 400;
        } // end else if
    } // End of with
};