You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, do you need any help from us?

USER: I want to book a direct flight ticket to meet my grandparents. Can you help me?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: I am comfortable with any time that you provide.

ASSISTANT: Ok, may I know your location airport codes?

USER: HOU  and MSP are my airport codes.

ASSISTANT: May I know your departure and arrival day?

USER: 02/23 and 02/25 are my trip dates.

ASSISTANT: Ok, do you have any other requirements?

USER: I would like to prefer an economy class.

ASSISTANT: Ok, could I have your name please?

USER: Myself Steven Baker.

ASSISTANT: Sorry, there is no flight with your request.

USER: No issue. Thank you.

ASSISTANT: You are welcome.