You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: I want to change my reservation, can you help me in that?

ASSISTANT: Sure, we are here to help you. Can I have your name to proceed further?

USER: I am Sandra Mitchell.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Thank you for your time, sorry no reservation found on your name.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.