You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

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

ASSISTANT: Sure, I will help you in change of flight ticket reservation. Please wait for a moment.

USER: I am Pamela Brown. Sure.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no flight reservation on your name to change it.

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

ASSISTANT: Thank you.