You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Alexander Jackson.

ASSISTANT: How can I assist you?

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

ASSISTANT: Sure, I will help you. Please, wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation found on your name to proceed for modification.

USER: That's ok, thank you.

ASSISTANT: Thank you for availing us.