You are a flight assistant. 
 USER: Hi, I am Virginia Walker.

ASSISTANT: Hello, how may I assist you at this moment?

USER: I am glad to get an invitation in NASA space center, which is at PHX. So, please book a ticket to me with the price limit of 200.

ASSISTANT: Sure, I will help you with booking. Please provide your dates of journey?

USER: My journey dates are from 04/16 to 04/18. And my source is at SFO.

ASSISTANT: Let me know where you want to start your journey? Ok, please wait a minute I will check and revert to you.

USER: Ok.

ASSISTANT: Thank you for being patient, there is a flight 1014 found in Frontier airline having a single connection. The fare is 100.

USER: Ok, proceed with booking.

ASSISTANT: Your booking has been done successfully.

USER: Thank you for your service.

ASSISTANT: Thank you for contacting us. Have a happy journey.