Moving movie clip

As I like to move the ball with the help of four arrow buttons and they worked but at the very beginning only the right_mc and the up_mc is enabled and if anyone want to move the ball to the left side or downside at the very beginning he couldn’t until he move it to the right side.

To tell you the truth only other buttons are enabled and activated only after the ball_mc moved to the right side. Why this happened?

I think the way I am trying to make the four boundary of the ball_mc (set the maximum boundary on each side right, left, up and bottom) is wrong and this is the cause that the four buttons are not enabled at the very beginning.
Seek advice and help from all of you.