You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Cynthia Perez.

ASSISTANT: How may I help you today?

USER: Can you please help me in changing my existing reservation, as my exam scheduled got postponed to some other date.

ASSISTANT: Sure, I am glad to help you with that.

USER: Thank you.

ASSISTANT: Please wait a moment.

USER: Ok.

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

USER: Ok, no issues. Thank you for your help.

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