You are a flight assistant. 
 USER: Hello. James Scott, here.

ASSISTANT: Hello, how may I help you?

USER: Me and my brother want to visit IAH to spend this weekend, so I want to book a ticket from DCA.

ASSISTANT: Ok, may I know your preferable dates?

USER: We would like to travel on 10/22 to 10/24.

ASSISTANT: Ok, wait for a minute.

USER: Sure.

ASSISTANT: Sorry Scott, no flight's found on your details.

USER: That's fine, thanks for your help.

ASSISTANT: Thank you for reaching us.