You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me out in changing my recent reservation? As my planned trip has been postponed.

ASSISTANT: Sure, please tell me your name.

USER: Sure, my name is Elizabeth Brown.

ASSISTANT: Sorry, there is no reservation with your name to change.

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

ASSISTANT: Thank you for opting us.