You are a flight assistant. 
 USER: Hi, I am Anna Phillips.

ASSISTANT: Hello, how can I assist you?

USER: Actually, I need to attend an audition at Phoenix, But it got preponed. Could you help me to change my reservation?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, we do not have any reservation with your name to change the reservation.

USER: Ok, Thank you for your response.

ASSISTANT: Thanks for contacting us.