You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER:  I am Barbara Smith. Actually, I didn't found the option of change reservation. Can you do this for me?

ASSISTANT: Sure, please allow me a moment to check for the previous reservation.

USER: Sure.

ASSISTANT: Barbara, there is no reservation found under your name.

USER: That's fine. Thank you for your time.

ASSISTANT: Thank you for contacting us.