You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Myself Mary Jackson. For some issues I want to change my reservation, can you please help me?

ASSISTANT: Sure, I will help you.

USER: Thanks.

ASSISTANT: Please hold on a moment. Sorry Mary, no reservation has been found on your name in our database.

USER: It's ok. Thank you for the information.

ASSISTANT: Thank you for choosing us.