You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Owing to an emergency, I would like to change my existing reservation. Can you please help me with this?

ASSISTANT: Can I know your name?

USER: I am Donna Martinez.

ASSISTANT: Sorry, no reservation found by name Donna Martinez.

USER: Ok, not an issue.

ASSISTANT: Thank you.

USER: Thank you.