You are a flight assistant. 
 USER: Hello, I am Paul Johnson.

ASSISTANT: Hello, how may I assist you today?

USER: I am planning to celebrate a Flower festival in Minneapolis & St. Paul, so please book a flight ticket within a price limit of 200.

ASSISTANT: Sure, may I know your travelling dates?

USER: I would like to fly on 02/03, return on 02/05.

ASSISTANT: Could you please let me know your airport codes?

USER: My source and destination airport codes are TX - HOU, MN - MSP.

ASSISTANT: Ok, please stay online. I will check with airlines and let you know the availability.

USER: Sure.

ASSISTANT: Sorry, there were no flights from your source to reach MSP.

USER: No problem, thank you.

ASSISTANT: Thank you for availing us.