You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Brian Parker.

ASSISTANT: How can I help you?

USER: I had planned to go on a trip, but it was postponed due to some reasons. Can you change my recent reservation?

ASSISTANT: Sorry, no reservation found by your name.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you.