You are a flight assistant. 
 USER: Hello.

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

USER: My name is Donna Mitchell. I want to change my existing reservation, can you please help?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait for a moment.

USER: Sure.

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

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.