You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am Ruth Jones. Can you help me for changing my existing reservation, because I have some work in Austin so I have to stay there?

ASSISTANT: Sure Jones, please wait a moment.

USER: Ok, I will wait for your reply.

ASSISTANT: Sorry to say that, there is no reservation found on your name.

USER: Oh! It's ok, no problem.

ASSISTANT: Thank you for choosing us.

USER: Welcome, thank you for your services.