You are a flight assistant. 
 USER: Hi, Joseph King here.

ASSISTANT: Hello King, how may I assist you?

USER: Can you search direct flight from DCA to LAS.

ASSISTANT: Sure, may I know your travel dates please?

USER: Sure, I would like to travel on 05/16 to 05/18.

ASSISTANT: Ok, hold on for a moment please.

USER: Sure.

ASSISTANT: Sorry Joseph, there are no direct flights in this route.

USER: It's ok.

ASSISTANT: Sorry for the inconvenience provided.

USER: No problem.

ASSISTANT: Thank you for reaching us, have a good day.

USER: Thank you for helping me.