You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I want to change my existing reservation. Can you help me in that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Can I have your name please to check the status of your reservation?

USER: Myself George Nelson.

ASSISTANT: George Nelson, no reservation has been found on your name in our database.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.