You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am Jessica Phillips. I want to change my existing reservation due to postponed of my exams dates. Can you please help me with this?

ASSISTANT: Sure, we are here to help you. Please wait a moment.

USER: Thank you. Sure.

ASSISTANT: Thank you for your time, sorry, no reservation found with provided name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for opting us.