You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you for the day?

USER: Richard Adams here. I'm planning to visit my grandparents, can you book a ticket from LAX to SFO?

ASSISTANT: When you are willing to travel?

USER: Sure, my planned departure and return travel dates are 18th and 20th of April.

ASSISTANT: Do you have any specifications?

USER: Yes, I want to return in the afternoon in a single connected flight.

ASSISTANT: Sorry, we found no flights on your given dates.

USER: That's ok, thank you for giving the information.

ASSISTANT: Thank you.