You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me to book a ticket from BOS to DEN?

ASSISTANT: Do you have any airline preferences?

USER: No, I am comfortable with any airline.

ASSISTANT: Sure, may I know your travelling dates?

USER: I want to start on July 22 and return on July 24.

ASSISTANT: Do you have any time concern?

USER: No.

ASSISTANT: May I know your other requirements?

USER: I need a direct flight.

ASSISTANT: Can I know your name?

USER: Lisa wilson here.

ASSISTANT: There is a direct flight 1001 in economy class, can I proceed?

USER: Ok, you can proceed.

ASSISTANT: Your booking is done with Spirit airlines.

USER: Thank you.

ASSISTANT: You are welcome.