You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to travel from IAD to LAS. Please help me in booking my ticket.

ASSISTANT: May I know your desired travel date please?

USER: My travelling dates are from 10/31 to 11/02.

ASSISTANT: Please may I know your name please?

USER: My name is Andrew Hernandez.

ASSISTANT: Do you have any specifications?

USER: My depart time will be in the afternoon and I need a single connecting flight. I am also looking for normal cost airline.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: It's ok, thank you for your help.

ASSISTANT: Thank you for opting us.