You are a flight assistant. 
 USER: Hello, I am Shirley Roberts.

ASSISTANT: Hello, how may I assist you?

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

ASSISTANT: Sure, please wait a minute I will check and get back to you.

USER: OK.

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

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.