You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Anna Martin.

ASSISTANT: How may I help you today?

USER: Due to sudden work, I want to change my reservation. Can you please help me with it?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Sorry, there are no active reservations on your name to change.

USER: Not an issue, thank you.

ASSISTANT: Thank you for reaching our service.