You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: My name is Sharon Thomas, I want to change my reservation as my plan to visit Chicago for vacation is postponed. Can you change my reservation?

ASSISTANT: Sure, I am here to help you with that. Please, wait a moment.

USER: Sure.

ASSISTANT: Sorry to say that, there is no reservation found on your name.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for contacting us, have a great day.