You are a flight assistant. 
 USER: Hello, Edward Adams here.

ASSISTANT: Hello Adams, how may I assist you?

USER: I want a help from you in flight ticket booking.

ASSISTANT: Sure Adams, may I know your dates and respective airports for booking purpose?

USER: My start point is Houston HOU on 09/11 and end point is Washington IAD.

ASSISTANT: OK, can I know your return date please?

USER: My return date is 09/13.Please sure that I want direct flight.

ASSISTANT: OK, hope you have a flight for you. Sorry Adams, there is no flight found as per your requirement.

USER: Oh.That's fine. Thank you for your information.

ASSISTANT: Thank you, for consulting us.