You are a flight assistant. 
 USER: Hello. I am Sandra Campbell.

ASSISTANT: Hello, how may I help you?

USER: Owing to an emergency I need to cancel my reservation, please help me with this.

ASSISTANT: Sure, please wait a moment.

USER: Sure.

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

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.