When a button, say b1, is pressed just for 2 seconds, the output led should be turned on and only when another button, say b2, is pressed or kept hold, the led should be off.
When b1 is pressed and hold for about 4 seconds, the led be on, and turned off only when b2 is either pressed or kept hold again.
In this case, the led should remain on and not be interfered by any signal inputs from b1.
Awaiting early solutions....
Thanks in advance.