You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Patrick Thompson.

ASSISTANT: How can I assist you?

USER: I would like to attend San Francisco this weekend. Could you please help me in booking the ticket from LAS to SFO?

ASSISTANT: Ok, may I know your travelling dates?

USER: I will drop-off 08/20 and again I will be return back on 08/22.

ASSISTANT: Sorry, no flights found on your route to reserve your ticket.

USER: Not an issue, anyhow thank you very much for your service.

ASSISTANT: Thank you for reaching us.