You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How best I can help you today?

USER: Can you please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: Sure, I am happy to help you. Will you give me your name to check your reservation status?

USER: Sure, I am Brandon Moore.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: We regret to inform you that, there is no reservation on your name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us.