You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I want to change my travel dates, can you please help me?

ASSISTANT: Sure, I am glad to help you. Can you please provide your name to check your previous reservation?

USER: Thanks, I have done my reservation on Patrick Hernandez.

ASSISTANT: Ok, please be on hold to check.

USER: Ok.

ASSISTANT: Sorry to inform you that, there is no reservation found with your name in our records.

USER: Oh! It's ok no problem. Thank you for your information.

ASSISTANT: Thank you for approaching us, have a great day.