You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I'm William Jackson here.

ASSISTANT: Nice to meet you William. How can I help you William?

USER: My final exam dates are postponed.Can you please help me for changing the existing reservation?

ASSISTANT: Sure William.

USER: Ok.

ASSISTANT: Just wait a minute, I will check in the database.

USER: Sure, take your time.

ASSISTANT: There is no reservation in our database with your name.

USER: No problem, I will check with another flight. Thank you for your information.

ASSISTANT: It's my pleasure, have a great day.