You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I want to change my reservation as already I book a flight to Charlotte to meet my friend is postponed due to my bad health. Can you help me with that?

ASSISTANT: I am sorry to hear that. I will help you.

USER: Thank you.

ASSISTANT: Please help me with your name.

USER: My name is Joseph Davis.

ASSISTANT: Thank you. Please allow me a minute.

USER: Sure.

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

USER: Ok, thank you for the information.

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