You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, we are here to help you. May I know your name?

USER: Please check under the name David Thomas.

ASSISTANT: Ok, wait for some time I will check and get back to you.

USER: Sure, I will stand by.

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

USER: That's ok, thank you.

ASSISTANT: Thanks for approaching us.