You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Please help me in changing my existing reservation, as my trip got postponed.

ASSISTANT: Sure, I am glad to help you with your concern. May I know your name to proceed further?

USER: Brian Collins here.

ASSISTANT: Can you please wait for a moment while I check the status of your reservation?

USER: Sure.

ASSISTANT: Thank you for waiting. Brian Collins, sorry as there is no active reservation found for the given name.

USER: That's ok, no issues. Thank you.

ASSISTANT: Anyway thank you for checking the status. Thank you for reaching us.