You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: My examination dates are postponed, so I need to change my ticket. Can you help me in changing my reservation?

ASSISTANT: Sure, may I know your name to check for the previous reservation?

USER: My name is Brian Perez.

ASSISTANT: Please allow me a moment to check for the previous reservation.

USER: Ok, take your time.

ASSISTANT: Brian, there is no reservation found under your name.

USER: It's ok, thank you.

ASSISTANT: You are welcome. Thank you for contacting us.