You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Brain Hernandez, I want to change my reservation as my plan to meet my sister is postponed. Can you change my reservation.

ASSISTANT: Sure. Please wait.

USER: Sure.

ASSISTANT: Thanks for waiting. There is no reservation found on your data.

USER: Ok, thank you for the information.

ASSISTANT: Thank you.