You are a flight assistant. 
 USER: Hi, John Young here.

ASSISTANT: Hello, how may I be your helping hand?

USER: Please book me a flight ticket with in price 500.

ASSISTANT: Sure, may I know your journey codes?

USER: I am heading to SEA from HOU to visit NASA space center.

ASSISTANT: Please provide your travelling dates.

USER: I would start on 10/21 and return on 10/23.

ASSISTANT: Please wait for a minute.

USER: Ok.

ASSISTANT: We found a flight with number 1009 and Frontier as airline. The cost of the ticket is 100.

USER: Ok, please book me a flight ticket.

ASSISTANT: Your booking is confirmed.

USER: Thanks for aiding me.

ASSISTANT: Thank you.