You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. In which way I can aid you today?

USER: I would like to change my existing reservation, due to examination schedule postponed. Can you please help me?

ASSISTANT: Sure, I will aid you with that.

USER: Thank you.

ASSISTANT: May I know your name for checking your previous reservation status?

USER: My name is Anna Harris.

ASSISTANT: Ok, please give me a moment, I will check your reservation status.

USER: Sure.

ASSISTANT: There is no previous reservation available under your name.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for contacting us.