You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: Can you please help me in changing my recent reservation? As my planned trip has been postponed to some other dates.

ASSISTANT: Sure, I will help you in changing the ticket.

USER: Ok.

ASSISTANT: Sorry, there are no reservations found in our database.

USER: How can you search for my previous reservation details without knowing my name?

ASSISTANT: Can I know your name please?

USER: My name is Nicole Mitchell.

ASSISTANT: Sorry, there are no reservations found under your name.

USER: Ok, thank you.

ASSISTANT: Thank you for reaching us.