You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Donna Green.

ASSISTANT: Donna Green, how may I aid you?

USER: I want to cancel my reservation, can you help me with that?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, no reservation is available by your name.

USER: Ok, thank you.

ASSISTANT: Thank you for choosing us.