You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Steven Harris from Washington.

ASSISTANT: How may I assist you today?

USER: I want to go to Houston next week, can you please book a flight ticket from DCA to HOU?

ASSISTANT: Sure, I am glad to help you with that. Can you please provide your planned dates of travelling?

USER: Thank you, I want to take off on 06/17 and book my return ticket also on 06/19.

ASSISTANT: Please wait a moment to check the flights availability.

USER: Ok.

ASSISTANT: We regret to inform you that, there are no flights moving to your region with your planned dates of travelling.

USER: Oh! It's ok no problem. Thank you for your service.

ASSISTANT: Thank you for approaching us, hope you have a great day.