I have a VB form with multiple buttons. When a user presses a button, it prints the button
value to a text box. Button values range from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

The text box needs to be cleared after a timeout period of around 15 seconds, but only if
no other buttons are pressed during this time interval.

I.E. the user can enter 1, and it clears in the text box after 15 seconds. But if the user
enters 1, 2, 3, then the timer interval should be reset to zero after button #3 is pressed
so 123 in the text box is cleared in 15 seconds.