You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am planning to attend  my friend marriage in Dallas, can you please make a reservation from DCA?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: I want to start my journey on July 6th, and arrival on July 8th.

ASSISTANT: Ok, could I have your name please?

USER: My name is Justin Evans.

ASSISTANT: Ok, do you need direct or connecting flight?

USER: I am comfortable with any flight.

ASSISTANT: Ok, do you have any other specifications?

USER: I don't have any other specifications.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: You are welcome, have a great day.