You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I want to change my existing reservation owing to an emergency.

ASSISTANT: Sure, let me check your reservation details in our database. Please mention your name.

USER: My name is Anna Robinson.

ASSISTANT: Anna Robinson, please wait for a while.

USER: Sure.

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

USER: Thank you.