You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Alexander Rodriguez. Owing to an emergency, I want to change my existing reservation. Can you help me?

ASSISTANT: Sure, we are here to help you. Please hold on a minute.

USER: Sure.

ASSISTANT: Sorry, there is no reservation on your name in our database.

USER: Ok, no issues. Thank you for your kind service.

ASSISTANT: Thank you for choosing us.