You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: Rachel Anderson here. I would like to change my flight existing reservation.

ASSISTANT: Fine, I can help you with that. Please wait for a while.

USER: Sure.

ASSISTANT: Rachel Anderson, there is no reservation found under your name to do modifications in that.

USER: Its alright, thank you very much for your time and help.

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