You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I want to change my existing reservation, as my friend's marriage got postponed.

ASSISTANT: Ok, please provide your name to check your reservation status.

USER: I am Thomas Brown.

ASSISTANT: Brown, no reservation has been found on your name in our database.

USER: Ok, not an issue.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your information.