You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Please book me a flight ticket from DEN to JFK to meet my school friends.

ASSISTANT: Ok, please can I know your dates of journey?

USER: I have planned to travel on Sept 19th and return on Sept 21st.

ASSISTANT: Ok, please let me know your name to proceed.

USER: Myself Melissa Thompson.

ASSISTANT: Is there any preferred connection limit you desired for?

USER: I prefer direct flight.

ASSISTANT: Ok, please let me know your specification your are looking for.

USER: I like economy class.

ASSISTANT: Sorry as per your need there is no direct flight available to book.

USER: Ok, no problem. Thank you.

ASSISTANT: Ok, thank you for choosing our agency.