You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: I want to book a flight ticket from DCA to SEA, can you please help me in booking?

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: I am planning to travel on Apr 20 and Apr 22 respectively.

ASSISTANT: Do you have any airline preferences?

USER: Yes, I need a normal cost airline with 1 stop over in between my journey.

ASSISTANT: Do you have any class preferences?

USER: I am looking for business class preference.

ASSISTANT: Do you have any other requirements that you are looking for?

USER: No.

ASSISTANT: Can you please provide your name to proceed further?

USER: Jennifer Brown here.

ASSISTANT: Sorry, there are no flights available at your request.

USER: That's fine, not an issue. Thank you for checking.

ASSISTANT: Thank you for contacting us, have a nice day.