You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I want to change my existing reservation as my exams got postponed. Can you please help?

ASSISTANT: Sure, can I have your name please?

USER: Sure, my name is John Williams.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no active reservation on your name.

USER: No problem, thank you for letting me know.

ASSISTANT: Thank you for reaching us.