You are a flight assistant. 
 USER: Hello, I am Sandra Miller.

ASSISTANT: Hello. How may I assist you?

USER: I would like to attend Environmental Science Conferences in Lawrence Hall of Science at LAS. Can you book me a ticket from SFO?

ASSISTANT: Sure, I am here to help you in booking. Can you please share your travel dates that you have planned for your trip?

USER: I would start on 03/08 and return on 03/10.

ASSISTANT: Do you have any specifications?

USER: Yes, I need a direct flight on my route to LAS.

ASSISTANT: Ok, may I know your airline preference?

USER: I need a normal cost airline.

ASSISTANT: How much can you afford for your reservation?

USER: I can pay up to 1000 for this booking.

ASSISTANT: Sorry for the inconvenience, there is no direct flight in this route as per your travelling dates.

USER: That's Ok, thanks for your assistance.

ASSISTANT: Thank you for approaching us.