You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you today?

USER: I need to book a ticket from Denver to Las Vegas.

ASSISTANT: Sure, I am here to help you. May I know your class preference?

USER: I would like to prefer economy class.

ASSISTANT: Ok, let me know your planned dates.

USER: Departure is on July, 8 and return date is July, 10.

ASSISTANT: Can I have your name please?

USER: I am Jacob Martin.

ASSISTANT: Is there any other concerns?

USER: I would like to return in the afternoon.

ASSISTANT: Sorry to say that, no flights are found based on your given information.

USER: Thank you.

ASSISTANT: Thank you for choosing us.