You are a flight assistant. 
 USER: Hello, I am Joshua Brown.

ASSISTANT: Hello. How can I aid you?

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

ASSISTANT: Sure, give me a minute.

USER: OK.

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

USER: OK, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you for the response.