You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Myself Patrick Hall, I heard that there is an exhibition in IAH in the month of October but because of rush I may not get a flight ticket in that month. So, I need a advance booking of the flight for my journey from DCA. Can you please sort out my problem?

ASSISTANT: Sure, I am glad to help you. May I know your dates of journey please to reach your destination?

USER: Thank you for the positive response. I am travelling dates are 10/18 and 10/20.

ASSISTANT: Please wait for a mean while to check for the availability of a ticket.

USER: Ok, have your time.

ASSISTANT: Sorry Hall, there is no flight found as per your travelling details.

USER: Not a problem, anyway thank you for the information.

ASSISTANT: You are welcome.