You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Alexander Nelson.

ASSISTANT: How may I assist you?

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

ASSISTANT: Ok, wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time, there is no reservation found on your name.

USER: That's ok, thank you.

ASSISTANT: Thanks for choosing us.