You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Samuel Campbell, want to change my previous reservation due to some emergency. Please help me out with that.

ASSISTANT: Sure, I will help you. Please wait a moment.

USER: Ok, take your time.

ASSISTANT: Samuel, no reservation has been found on your name in our database.

USER: It's ok, thank you for you help.

ASSISTANT: Thank you for choosing us. Have a nice day.