You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I want to change my existing reservation, can you please help me with this?

ASSISTANT: Sure, I am here to help you. Can you please share your name to check your previous reservation status?

USER: I am Matthew Wright.

ASSISTANT: Ok, please give me a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name in our records.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.