You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Helen Thomas.

ASSISTANT: How may I lend a hand to?

USER: Can you help me in changing my recent reservation, as my exam is postponed?

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

USER: Sure.

ASSISTANT: Thomas sorry for inconvenience, no reservation is found with your criteria.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you Thomas for approaching our agency.