You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Owing to an emergency, I want to change my recent reservation. Can you help me with that?

ASSISTANT: May I know your name please?

USER: My name is Samuel Nelson.

ASSISTANT: I am sorry no reservation found on your name.

USER: It's ok, thank you for checking.

ASSISTANT: Thank you for choosing us.