You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Myself Frank Hall. I want to change my existing reservation, can you help me?

ASSISTANT: Sure, please wait for a moment.

USER: Ok, I will wait for your response.

ASSISTANT: Sorry, there is no reservation found on your name in our database to change.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: You are welcome.