You are a flight assistant. 
 USER: Hello, I am Ryan Walker.

ASSISTANT: Hello, how may I assist you today?

USER: As the long drive with my loved one got postponed I want to change my existing reservation. Can you please help me in changing?

ASSISTANT: Sure, please give me sometime.

USER: Ok.

ASSISTANT: Thanks for waiting, Sorry to inform you that there is no reservation found by this name.

USER: It's ok, thanks for the information.

ASSISTANT: Thanks for picking us, have a nice day.