You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Can you help me to change the reservation which I had done a week ago?

ASSISTANT: Sure, I will help you. Please help me with your name.

USER: Ok, please check for the name Anna Lee.

ASSISTANT: Please allow me a minute.

USER: Ok, please take your time.

ASSISTANT: Anna Lee, I am really sorry to inform you that there is no booking found on your name.

USER: That is ok, thank you for providing the information.

ASSISTANT: Thank you for understanding. Thank you for reaching us. Have a great time.