You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Jonathan Green.

ASSISTANT: How may I be of your help?

USER: I want to change my reservation as my project submission date got postponed. Can you help me?

ASSISTANT: Sure, please wait a moment I will check the reservation list.

USER: Ok.

ASSISTANT: Thank you for waiting, I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: That's Ok, thanks for the response.

ASSISTANT: Thank you for reaching us.