You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you out?

USER: I want to change my reservation, can you help me with that?

ASSISTANT: Sure, I will help you in changing the reservation. May I know your name please?

USER: Jeffery Roberts here.

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

USER: Ok, thank you.

ASSISTANT: Thank you for reaching us.