You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Carol Miller.

ASSISTANT: How can I assist you today?

USER: I want to change my existing reservation, can you help me?

ASSISTANT: Ok, I will check for the reservation please wait.

USER: Thank you. I will wait for your response.

ASSISTANT: Sorry, there is no reservation been found on your name to change.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: You are welcome, thank you for choosing our agency.