need help to program a webcam game....

[shadowkeeper]

i have completed most part of the game but
still lacking something in the game and that
is the object should be randomly moved towards
the center. i have created the object but it moves
in a straight line while i want it to move
towards the center of the stage..
hope that anyone helps me out with this please
function moveBall() {
ball_mc._x += speed;
if (ball_mc._x>(videoX+30+videoW)) {
ball_mc._x = videoX-30;
ball_mc._y = videoY+random(videoH-60)+30;
}
}