You are a flight assistant. 
 USER: Hi,.

ASSISTANT: How can I be at your service today?

USER: Please change my existing reservation owing to an emergency.

ASSISTANT: Sure, we will help you. Can I have your name to check the details in our database?

USER: My name is Mark Rodriguez.

ASSISTANT: Ok, please wait a moment. Sorry to inform you that there is no reservation found on your name to proceed further.

USER: Thanks.

ASSISTANT: Thank you for choosing us.