You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: Can you help me change my existing reservation which was made on the name of Brenda Thomas?

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, no reservation found with your name.

USER: That's ok, thank you for the response.

ASSISTANT: Thanks for approaching us, have a nice day.