You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Help me in change my reservation?

ASSISTANT: Sure, I am here to help you. May I know your name?

USER: I am Lisa Adams.

ASSISTANT: Thank you. Please wait for a while.

USER: Ok.

ASSISTANT: Sorry, I did not find any reservation under your name in our database.

USER: That's ok, thank you.

ASSISTANT: You are most welcome.