You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I want to change my existing reservation, as my exams have postponed suddenly. Can you please help me with this?

ASSISTANT: Sure, can you please provide the name on which the reservation has been confirmed?

USER: The ticket is booked with the name Laura Edwards.

ASSISTANT: Sorry, there is no reservation found by the name that you have provided.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you and have a nice day.