You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to change my reservation which was done yesterday, as my plan to visit Chicago to meet my uncle got postponed. Can you help me with that?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: May I know your name?

USER: My name is Eric Jackson.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation found under your name.

USER: Ok, thank you for the information.

ASSISTANT: Most welcome.