You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I serve you today?

USER: Can you please change my existing reservation?

ASSISTANT: Sure, may I know your name to proceed further?

USER: Sure, I am Jacob Williams.

ASSISTANT: Please wait for a while I will check and let you know about your reservation status.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name to change.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for connecting with us.