Countdown_timer

It includes the below functionalities:

1. Quit - To STOP and quit the window
2. Set - After entering the seconds, to set the other options (start, pause & resume) i) Start - To start the timer, The TIME LEFT will be displayed below. ii) Pause - To pause or freeze the timer iii) Resume - To resume or continue the Timer
3. Reset - To reset Hour, Minutes, and Seconds to 0.