I did go to Denver DO office today morning. I first went to the satellite office, where i had my Interview. The security officer told me to go to main office which is across the street. I went to main office and explained the situation to security officer. He initially told me that i need to have appointment. But after explaining the problem, he told me to go and stand in front of the counter 1 and they will assist me. I was called instantaneously at counter 1 and i explained the problem. She took my letter and the signed N-400 page and told me that she will pass it on to the IO officer. I ask for acknowledgement, she told they don't do any acknowledgement. I will be informed by USmail..whatever. It took appox. 10 mins.
Unfortunately, we don't have access to the IO officer. We have to give all the necessary documents in the counter and they will pass it on.
I signed all the places like photos and other documents which they presented during the interview. I wasn't told to sign on the N-400 appln last page. It was IO job to take the full signature on N-400 after the interview.
Thanks for your support guys!!