You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I support you?

USER: I am Kimberly Miller. Due to some personal work I want to change my existing reservation.

ASSISTANT: Sure, please give me a minute, I will check the existing reservation to change it.

USER: Sure.

ASSISTANT: Thank you for your patience, we are sorry to say that there is no reservation found on your name.

USER: OK,no problem. Thank you for your service.

ASSISTANT: Thank you for availing our agency.