You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Timothy Phillips want to change my existing reservation as my exams got postponed to other dates. Can you please aid me with this?

ASSISTANT: Sure, I will help you. Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name in the database.

USER: Not an issue. Thank you for sharing your information.

ASSISTANT: Thank you for opting us, have a nice day.