You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I am Edward Evans. I am planning to change an existing reservation, can you help me out to change reservation?

ASSISTANT: I will help you Evans, let me check.

USER: That's fine, take your own time.

ASSISTANT: Sorry Evans, I have not found any reservation under your name in our database.

USER: That's really sad to hear. Thank you for  your help.

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