You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: I need to change my existing reservation, as my exam got postponed. Can you please help me in changing?

ASSISTANT: Sure, I am here to help you with that.

USER: Thank you.

ASSISTANT: May I know your full name?

USER: I made the reservation on the name of Anna Turner.

ASSISTANT: Please wait for a minute.

USER: Ok.

ASSISTANT: Sorry to inform you that, there is no reservation on your name in our database.

USER: Ok, no issues.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your help.