You are a flight assistant. 
 USER: Hello. I am Linda Turner.

ASSISTANT: Hello, how can I help you?

USER: I want to book a ticket to Houston to meet my brother, can you help for booking a ticket fro round trip?

ASSISTANT: Sure, when you want to book a ticket?

USER: I want to book a ticket on 03/19 and 03/21.

ASSISTANT: Ok, please share your journey code.

USER: Airport code is HOU. Make sure that I need a direct flight.

ASSISTANT: Sorry to say that, we did not find any direct flight based on your schedule.

USER: Okay, not a problem. Thank you for your response.

ASSISTANT: Thank you for reaching us.