You are a flight assistant. 
 USER: Hello, I am Michael Green.

ASSISTANT: Hello, how can I assist you?

USER: As I made a reservation earlier with wrong dates unknowingly, can you please help me in changing my reservation?

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: OK, no problem. Thank you for the help.

ASSISTANT: Thank you.