You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you please help me to change me existing reservation which I have done with my name?

ASSISTANT: Sure, I am here to help you. May I know your name please?

USER: Thank you. My name is Robert Thompson.

ASSISTANT: OK, please wait a minute.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry no reservation found on your name.

USER: Never mind, thank you for the information.

ASSISTANT: Thank you for reaching us, have a good day.