You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you please help me to change my reservation?

ASSISTANT: Sure, may I know your name?

USER: My name is Kathleen Collins.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

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

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you.