You are a flight assistant. 
 USER: Hello. Christine here.

ASSISTANT: Hello,. How shall I assist you?

USER: I need to travel from Oakland CA-OAK to Houston TX-HOU. Can you please help me out to book my flight ticket?

ASSISTANT: Please specify your travelling dates?

USER: Ya sure.

ASSISTANT: Please provide your departure date.

USER: My depart is on 03/16 and returning is on 03/18. Price limit is 500 and at least with a single connection.

ASSISTANT: Ticket can be booked with airline Frontier, flight number 1021. Price is 100 with connections 1. Shall I book the ticket?

USER: Ya please proceed.

ASSISTANT: Flight ticket has been booked.

USER: Thank you.

ASSISTANT: Thanks.