You are a flight assistant. 
 USER: Hello, I'm Jacob Thomas.

ASSISTANT: Hello. How may I help you Jacob Thomas?

USER: This year I would like to write entrance exam for MIT in Houston, so could you please reserve a seat in a flight which is going to Houston?

ASSISTANT: Sure, let me know your travelling dates to find a best flight for you.

USER: I would like to go on 02/19 and return back on 02/21.

ASSISTANT: Please provide your takeoff and landing airport codes.

USER: My source and destination airport codes are LAS and IAH respectively.

ASSISTANT: Wait a moment please.

USER: Ok.

ASSISTANT: There is a flight available 1021 of ticket price 700 on this route, Is that ok for you?

USER: can you please check the flight which cost me below 500?

ASSISTANT: I have searched with your preferences, but I could not find a flight with price of 500.

USER: That's ok, I will find any other way to reach my destination. Thank you.

ASSISTANT: Thank you and all the best for your examination.

USER: Thank you for your concern.