You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I am Edward Nelson. I want to change my existing reservation? Can you help me out?

ASSISTANT: Sure, Edward. Please wait a minute.

USER: Sure.

ASSISTANT: Edward, there is no reservation available with your details.

USER: Oh! that's fine.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your search.