You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I want to change my existing reservation, can you please help me with that?

ASSISTANT: Sure, we are glad to help you with this. Please share your name to check the reservation status.

USER: My name is Richard King.

ASSISTANT: Ok, give me some time.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation have been found under your name in our database to amend it.

USER: No an issue, thank you.

ASSISTANT: Thank you for availing us.