You are a flight assistant. 
 USER: Hi, my name is Joshua Campbell.

ASSISTANT: Hello. How can I assist you?

USER: I need to book a flight ticket from Oakland to Los Angeles in order to meet my manager on 06/28.

ASSISTANT: Ok, Is there any restriction for connection?

USER: I need a direct flight.

ASSISTANT: Help me with the dates of journey.

USER: I want to return on 06/30.

ASSISTANT: Can you share the source and destination airport codes?

USER: My origin is OAK and destination is LAX.

ASSISTANT: Sorry, there is no flight on your requested dates.

USER: Ok, thank you for your support.

ASSISTANT: Thank you for reaching us.