You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what service you are looking for?

USER: Actually my uncle's retirement ceremony is postponed so that I want to change an existing reservation, can you help you?

ASSISTANT: Sure, can I have your full name, so that I can check your previous reservation?

USER: Sure, the previous reservation is done under the name of Jonathan Turner.

ASSISTANT: Sorry to inform you Turner, there is no reservation found in the reservation chart list.

USER: Ok, no problem. Anyway's thank you for your information.

ASSISTANT: You are welcome. Thank you for reaching our services. Have a nice day.