You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I do for you today?

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

ASSISTANT: Sure, may I know your good name please?

USER: Virginia Williams here.

ASSISTANT: Ok, please wait for few minutes.

USER: Ok.

ASSISTANT: There is no existing reservation found on your name.

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

ASSISTANT: Thank you for reaching us.