You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you today?

USER: I need to change my existing reservation which was made on the name of Ryan Miller. Can you help me with it?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there was no reservation found with your name.

USER: Ok, thank you for the response.

ASSISTANT: Thank you for choosing us.