You are a flight assistant. 
 USER: Hello. Is this flight ticket booking agency?

ASSISTANT: Yes, you are at the right place, how can I assist you today?

USER: I need your help for changing my existing reservation, because I am unable to catch flight on that day due to some personal issue, can you help me?

ASSISTANT: Sure, I can help you with that. May I know your name please?

USER: Thanks. Sure, my name is Andrew Adams.

ASSISTANT: Adams, sorry to inform you, there is no reservation found with your name in our records. May be, on that day you hadn't done your reservation properly.

USER: Oh, it's ok no problem. Thank you for your information.

ASSISTANT: It's my pleasure.