You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: My business trip has been postponed, can you please help me for changing the existing reservation?

ASSISTANT: Sure, please help me with your name to check your details.

USER: Sure, my previous reservation is on the name of Gary Walker.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Ok, no problem.

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

USER: Thank you for your information.