You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Elizabeth Perez. Due to sudden changes, my exams has been postponed. Can you please help me to change my reservation?

ASSISTANT: Sure, I will help you to change your existing reservation.

USER: Thank you.

ASSISTANT: Please allow me a moment.

USER: Ok.

ASSISTANT: Sorry, no reservation found on your name to change your reservation.

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

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