Hi all, i got this circuit for a combination lock from pcbheavens.com but i am not able to figure out the part of the separate part of the ckt on the top right. I need ur help in figuring out where it goes or is it something else. Plz help me out. This is the link for the ckt http://pcbheaven.com/circuitpages/images/simplekeycodelock_1263053976.png