You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: I am Dennis Moore want to travel to Houston, can you please book me a ticket for direct flight?

ASSISTANT: Sure, may I know your travel dates?

USER: My travel dates are from 09/22 to 09/24.

ASSISTANT: Could you please let me know your airport codes to check the flight availability?

USER: I want to start my journey from Las Vegas, NV-LAS to Houston, TX-HOU.

ASSISTANT: Do you prefer economy or business class?

USER: I prefer an economy class ticket.

ASSISTANT: We found a flight on your details with airline AA, flight number: 1000. Shall I reserve this ticket?

USER: If it is a direct flight, please proceed.

ASSISTANT: Sorry Dennis Moore, there is no direct flight on your route.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you.