You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: I want to change my existing reservation due to some technical issues. Can you help me in doing that?

ASSISTANT: Sure, may I know your good name?

USER: I am Lisa Lewis.

ASSISTANT: Please wait for a moment, while I check for the reservation.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our system data.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for visiting us, have a nice day ahead.