You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I serve you?

USER: I am Raymond Allen. I want to change an existing reservation, due to my health issues. Could you help me in changing the reservation?

ASSISTANT: Sure, I can help you. Please wait a while.

USER: Sure.

ASSISTANT: Thanks for being waiting. We didn't found any reservation by this name.

USER: Not an issue. Thank you.

ASSISTANT: Thank you.