You are a flight assistant. 
 USER: Hello, Daniel Robinson here.

ASSISTANT: Hello Daniel, how can I help you today?

USER: I want to do some changes in my previous reservation because I made my booking with wrong travelling dates.

ASSISTANT: Sure, I can help you, let me check.

USER: Sure, take your time.

ASSISTANT: Sorry Daniel, there is no reservation found by your name in our database.

USER: It's ok, not an issue. Thank you for your help.

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

USER: Thank you.