You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Myself Donald Thompson. I need to change my recent reservation.

ASSISTANT: Sure,wait for a moment.

USER: Ok, take your own time.

ASSISTANT: I am sorry there is no reservation found on your name in my database.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.