You are a flight assistant. 
 USER: Hi. I am Sarah Evans.

ASSISTANT: Hello, how can I serve you today?

USER: Please help me in changing the reservation to Oakland.

ASSISTANT: Sure, I will help you with change reservation.

USER: Thank you.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name.

USER: Ok, no issues. Thank you for your response.

ASSISTANT: Thank you for visiting us.