You are a flight assistant. 
 USER: Hello. Timothy Lee here.

ASSISTANT: Hello Timothy, how may I help you?

USER: Due to heavy rainfall, I want to postponed my trip. Can you alter my reservation?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found with your name in our records.

USER: It's ok. Anyway, thank you for searching.

ASSISTANT: You are welcome.