You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: This is Donna Jones. I want to change my existing reservation. Can you help me in that?

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time, there is no reservation found in your name to change.

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

ASSISTANT: Thank you for choosing us.