You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Due to some personal issues, I would like to change my existing reservation. Can you help me?

ASSISTANT: Sure, I will help you with this. May I know your name please?

USER: My name is Dorothy Hill.

ASSISTANT: Ok, please wait for a moment.

USER: Ok, take your time.

ASSISTANT: Sorry Hill, there is no reservation found as per your name to change your reservation.

USER: Its ok, thank you for the information.

ASSISTANT: You are welcome.