You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I best serve you today?

USER: I am Thomas Miller. I want to change my existing reservation. Could you help me with that?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no recent reservation found on the given name.

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

ASSISTANT: Thank you.