You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you today?

USER: I am Elizabeth Lewis. I would like to change my existing reservation, can you please assist me in changing?

ASSISTANT: sure, we are perky to help you. Please wait for a while.

USER: Sure.

ASSISTANT: There is no reservation found on your name in our database.

USER: Ok, no worries at all. Thank you.

ASSISTANT: Thank you for opting us.