You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you at this moment?

USER: Please help me to update my travelling dates in my existing reservation.

ASSISTANT: Sure, I am here to help you with that. Can you please share your name to check your reservation status?

USER: I am Helen Martin.

ASSISTANT: Ok, please give me a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name in our records.

USER: That's ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us.