You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: I am Mary Campbell. Can you help me to change my reservation to next week?

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

USER: Sure, take your time.

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

USER: That is fine. Thank you for your time.

ASSISTANT: Thank you for contacting us.