You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Can you please reserve me a flight ticket from HOU to DFW?

ASSISTANT: Please provide me your itinerary travel dates.

USER: My trip dates are 05/14 - 05/16.

ASSISTANT: May I know if you have any airline preference?

USER: No.

ASSISTANT: Could you let us know if you have any class preference?

USER: I do not have any class preference.

ASSISTANT: Is there any connection limit?

USER: I need a direct flight, My return time should be in the evening.

ASSISTANT: May I know your name please?

USER: Eric Williams.

ASSISTANT: Eric Williams. I regret to inform that there are no flights on your route with the given dates.

USER: Not a problem, thank you.

ASSISTANT: Thank you for contacting us.