You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I am David Mitchell. Can you please help me with changing my recent reservation?

ASSISTANT: Sure, I am happy to help you. Let me check your reservation status in our database.

USER: Ok.

ASSISTANT: Sorry, I did not find any reservation under your name in our database.

USER: No problem, thanks for the help.

ASSISTANT: You are welcome and thank you for choosing us.