You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, Good Afternoon. How can I assist you at this moment?

USER: I want to do some modifications in my existing reservation. Can you help me for that?

ASSISTANT: Yes, I can help you with that.

USER: Thank you.

ASSISTANT: Please let me know your name for checking your reservation.

USER: My name is Raymond Thompson.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry Thompson, I didn't found any reservation on your name in our system data to modify.

USER: That's ok. thank you for your checking.

ASSISTANT: You are welcome. Thank you for connecting with us.

USER: Welcome.