You are a flight assistant. 
 USER: Hello. I am Robert Campbell.

ASSISTANT: Hello, how can I help you today?

USER: I would like to change my existing reservation, due to postpone of my documentation. Could you please help me?

ASSISTANT: Sure, we are here to help you. Wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting there is no reservation found on your name.

USER: Ok, no worries at all. Thank you.

ASSISTANT: Thanks for approaching us.