You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

USER: I am Sandra Miller.

ASSISTANT: How can I assist you today?

USER: I made a earlier reservation to attend a meeting, due to some issues it got postponed.

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

USER: Thank you.

ASSISTANT: Sorry, there are no reservations found.

USER: Ok, no issue.

ASSISTANT: Thank you for reaching us.

USER: Thank you.