You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Katherine Anderson.

ASSISTANT: How could I oblige you today?

USER: Owing to an emergency, I have to change my previous flight ticket booking. Can you please help me in that one?

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: There is no reservation found with your given name in our data base.

USER: I think it not booked while I was booking, thank you for your immediate help.

ASSISTANT: Thank you for opting us.