You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I would like to change my flight reservation as my trip got postponed, can you please help me?

ASSISTANT: Sure, please provide your name.

USER: I am Jack Lee.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thank you for being patient, we did not find any reservation on your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for opting us.