You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: I am Nicholas Robinson here. I would like to change my existing reservation, which is done recently, Can you please help me out?

ASSISTANT: Sure, I will help you.

USER: Thank you for considering my request.

ASSISTANT: Sorry, there are no reservations found in our database.

USER: Not a big problem, anyway thank you for the information.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your help in searching.