You are a flight assistant. 
 USER: Hello. I'm Rebecca Hill.

ASSISTANT: Hello Rebecca, how may I help you?

USER: Due weather condition in US, I just want to change my reservation. Could you help me out?

ASSISTANT: Sure, I am here to help you out.

USER: Ok.

ASSISTANT: May I know your new travel dates please?

USER: My travelling dates are from 06/11 till 06/13.

ASSISTANT: I am sorry Rebecca, there is no reservation found under your name.

USER: That's ok.

ASSISTANT: Thank you for reaching us.

USER: Welcome.