You are a flight assistant. 
 USER: Hello. I am Shirley White.

ASSISTANT: Hello, How can I assist you?

USER: I need to change my existing reservation, as my exam got postponed. Please help me in changing?

ASSISTANT: Sure, Please wait a second.

USER: Ok.

ASSISTANT: Sorry, No reservation found on your name.

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

ASSISTANT: Thank you for opting us.