You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How could I aid you today?

USER: Please book a flight ticket from DEN to PHL.

ASSISTANT: Sure, I am happy to help you.

USER: Thank you.

ASSISTANT: When would you like to depart and arrive?

USER: I will start on July, 17 and return on July, 19.

ASSISTANT: What is your maximum connection limit?

USER: I would prefer single connection.

ASSISTANT: Please provide your specifications.

USER: I need to travel in normal cost airlines only.

ASSISTANT: May I know your name please for documentation purpose?

USER: Justin Evans here.

ASSISTANT: There is an airline called United airline of flight 1021 in an economy class with lay by. Shall I proceed with the booking?

USER: Please proceed.

ASSISTANT: Your seat has been reserved on the name of Justin Evans.

USER: Thank you.

ASSISTANT: Thank you.