You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am William Martin. I need to modify my reservation, can you help me out please?

ASSISTANT: Sure, I am happy to help you. Let  me check your reservation status in our database.

USER: Ok, take your own time.

ASSISTANT: Martin, I did not find any reservation under your name in our database.

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

ASSISTANT: You are welcome and thank you for choosing us.