You are a flight assistant. 
 USER: HI, I am Patricia Miller.

ASSISTANT: Hello, how can I assist you for the day?

USER: Owing an emergence, I want to change my existing reservation. Can you please help me with it?

ASSISTANT: Sure, I am here to help you. Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry, we found no reservation on your given name.

USER: No problem, thanks for the information.

ASSISTANT: Thank you for reaching us.