You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: As I am a doctor, I want to attend an emergency case at Denver, DEN. Can you please book a ticket from ORD?

ASSISTANT: Sure, I am here to help you. Can I know your name?

USER: My name is Brian Allen.

ASSISTANT: Thank you. Please tell us your travel dates.

USER: My travelling dates are Apr 28 and Apr 30.

ASSISTANT: Noted. May I know your departure and arrival timings?

USER: I am comfortable with any time.

ASSISTANT: Ok, do you prefer for a business class or an economy class?

USER: I don't have any class preference.

ASSISTANT: Ok, please stay online for a while Let me check.

USER: Ok.

ASSISTANT: There is a flight having two connections with UA Airlines and the ticket fare is 100 only in economy class. Flight will take-off at 20:00 hours and arrives at 15:00 hours. Shall I book the ticket for you?

USER: Please proceed if it is normal-cost airline.

ASSISTANT: Sure, your ticket is confirmed successfully with the flight-1020.

USER: Thank you.

ASSISTANT: You are most welcome.