You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I help you?

USER: Can you please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: Sure, May I know your name?

USER: Sure, my name is Brenda Robinson.

ASSISTANT: 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.