You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: Yesterday I have booked a ticket for Dallas but your agent misplaced my origin code from Philadelphia, PHL to Boston. So can you please help me to change an existing reservation?

ASSISTANT: Sure, may I know your name please?

USER: My name is David Moore.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, no reservation found with your name to change.

USER: Ok, no worries. Thank you.

ASSISTANT: Thanks for opting us.