You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I am Patrick Smith. Due to the heavy rains, I want change my reservation. Can you help me?

ASSISTANT: Please wait a while.

USER: Ok, take your own time.

ASSISTANT: Sorry to say, there is no reservation on your name in our database.

USER: It's ok, thanks for checking.

ASSISTANT: Thank you for opting us.