You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Nicholas Hill.

ASSISTANT: How may I help you?

USER: I want to book a ticket from ATL to LAX to meet my brother in Los Angeles.

ASSISTANT: On which dates you are willing to travel?

USER: My desired travel dates are 06/28 and return on 06/30.

ASSISTANT: Sorry, there is no flight available on these dates.

USER: It's ok, thank you for your information.

ASSISTANT: Most welcome.