You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Charles Miller.

ASSISTANT: How can I aid you today?

USER: Can you help me in changing my recent reservation?

ASSISTANT: Let me check the reservation status.

USER: Sure.

ASSISTANT: We couldn't found any reservation details in our database.

USER: Its ok.

ASSISTANT: Thank you for choosing us.

USER: Thank you.