You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Alexander Davis.

ASSISTANT: How may I assist you today?

USER: Can you please book a flight ticket from DEN to SFO?

ASSISTANT: Sure, I can help you with that. May I know your preferable travel dates please?

USER: Sure, I need to travel on dates of 07/12 and 07/14.

ASSISTANT: Ok, please wait for a while.

USER: Sure, take your time.

ASSISTANT: Spirit airlines is having a flight on that route with ticket fare of 100, shall I proceed for booking?

USER: That is fine, please proceed with booking.

ASSISTANT: I have successfully booked your ticket with flight-1005, have a safe journey.

USER: Thank you for your help.

ASSISTANT: Thank you for choosing us.