You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I would like to change my flight reservation as my trip got postponed, can you please help me?

ASSISTANT: Sure, I am here to help you with that. May I know your name?

USER: My name is Daniel Lopez.

ASSISTANT: Ok, wait for a minute.

USER: Sure.

ASSISTANT: We are regret to inform you that, there is no reservation found on your name in our database.

USER: No issue, thank you for the help.

ASSISTANT: Thank you for reaching us.