You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I am Edwards Moore. I want to book a ticket from LAS to IAD to attend seminar, can you help me in booking?

ASSISTANT: Sure, I am here to help you out. Please provide me your trip dates.

USER: I am departing on 04/28 and return on 04/30.

ASSISTANT: Sorry Edwards Moore, there is no flight with your travel dates.

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

ASSISTANT: Thank you for reaching us.