You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Linda Carter here.

ASSISTANT: Linda, how can I render you today?

USER: I want to participate in Boston marathon, so please book my ticket from Denver.

ASSISTANT: Sure, I am mirthful to help you. May I know your airport abbreviates please?

USER: My airport codes are DEN and BOS.

ASSISTANT: Ok, may I know your travel dates please?

USER: My itinerary dates are 09/21 and 09/23.

ASSISTANT: Ok, hold on for a moment. Let me check the best flight for you.

USER: Sure.

ASSISTANT: I found a flight for you with UA airline and it costs you 1100. Shall I proceed to reserve a seat in this particular airline?

USER: Please book my ticket.

ASSISTANT: Your ticket has been booked with 1028 flight number.

USER: Thank you.

ASSISTANT: Welcome, thank you for choosing us.