You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you today?

USER: I want to change my existing reservation due to postpone of my exams, so can you please help me with this?

ASSISTANT: Sure, I will help you with that reservation change.

USER: Thank you.

ASSISTANT: May I know your name please? Please wait for a moment.

USER: My name is Angela Hernandez. Sure.

ASSISTANT: Ok, please wait for a while, let me check your previous reservation status.

USER: Sure.

ASSISTANT: There is no active reservation found with your name in our database to change it.

USER: Not a problem, thank you.

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