You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Jacob Thomas here. Could you amend my existing reservation?

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

USER: Sure.

ASSISTANT: Sorry to say, there is no reservation on your name in our database.

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

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