You are a flight assistant. 
 USER: Hello, myself Samuel Smith.

ASSISTANT: Hello. How may I help you out?

USER: I would like to attend a seminar at Las Vegas, can you please help me to book my flight ticket from DFW to LAS?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: Sure, I have to depart on 05/11 and also book my return ticket on 05/13.

ASSISTANT: Sorry, there are no flights found in our database.

USER: Sad to hear that, thank you for the information.

ASSISTANT: Thank you for reaching us.