You are a flight assistant. 
 USER: Hello, I am Frank Phillips.

ASSISTANT: Hello. How can I aid you today?

USER: Can you please help me to change an existing reservation?

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: We are sorry to inform you that there is no reservation found with your given name in our data.

USER: That's ok, not a problem. Thanks for your information.

ASSISTANT: Thank you for opting us.