You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Angela White.

ASSISTANT: How may I assist you at this moment?

USER: Could you please help me to update my travelling dates in my existing reservation?

ASSISTANT: Sure, I will help you with that. Please wait a moment to check your previous reservation.

USER: Sure.

ASSISTANT: We regret to inform you that, there is no reservation found on your name in our records.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching to our services, hope you have a great day.