You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: With the name of David Wilson, change the reservation as my scheduled journey dates are postponed.

ASSISTANT: Sure, Please hold on.

USER: Ok.

ASSISTANT: Thank you for your time. No reservation found on your name.

USER: Ok, thank you for your quick response.

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