You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you today?

USER: I am Brian Hernandez want to attend a business meeting, can you help me to book a direct flight?

ASSISTANT: Sure, may I know your travelling dates?

USER: Sure, I want to travel on 07/18 and intend to return back on 07/20.

ASSISTANT: Ok, can you provide me your exact airport codes?

USER: Yes, I want to fly from IAD to DFW.

ASSISTANT: Sorry no flight's available based on your connection limit.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.