You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you please help me to change my existing reservation?

ASSISTANT: Could you provide your name?

USER: I am Ruth Evans.

ASSISTANT: Ok. Let me check details with your recent reservation.

USER: Sure.

ASSISTANT: Sorry, there is no reservation by your name.

USER: Ok, not an issue.

ASSISTANT: Thank you.

USER: Thank you for the information.