Event structures are driven by user-interface events. A programmatic change to a control's value is not a user-interface event. But you can write to the "Value (signaling)" property instead; this mimics a user-interface event and will trigger your event structure.
By the way, I suggest you put a delay in each of your loops. Otherwise they'll run as fast as they can, which will bring your computer to its knees. For the simple While loop, a Wait (ms) subVI will do; any non-zero value for the wait will keep your computer happy. For the loop containing your event structure, you can wire a non-zero positive value to the hourglass icon at the upper left corner to achieve the same thing.