You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. My I know how best I can help you today?

USER: As I am a doctor, I want to attend an emergency case at Houston, HOU. Can you please book a ticket from DCA?

ASSISTANT: Sure, we are happy to assist you in booking. What dates would you like me to book this plane ticket for you?

USER: My travelling dates are Jan 21 and Jan 23.

ASSISTANT: Do you need a lay by in between your journey?

USER: Yes, I want single connection.

ASSISTANT: Would you like to avail any benefits for the comfort of your journey?

USER: I prefer business class.

ASSISTANT: May I know your name please?

USER: I am Ruth Williams.

ASSISTANT: Ok, please wait a moment I'll search best flight for you.

USER: Ok.

ASSISTANT: Thank you for waiting, we are unable to provide flight in between your journey routes due to some technical up-gradation at destination airport.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for approaching us.