You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Sharon Roberts.

ASSISTANT: Roberts, how may I aid you today?

USER: I want to change my reservation.

ASSISTANT: Sure, I will help you with that, please hold on for a moment to check your reservation status.

USER: Sure.

ASSISTANT: Roberts, I did not find any reservation with your name in my database.

USER: That's ok. Thanks for your help.

ASSISTANT: Thank you for reaching us.