You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: Can you please help me in booking a flight ticket from Washington, IAD to Houston, IAH?

ASSISTANT: Sure, I am happy to help you with that. Can I have your travel dates please?

USER: My journey dates are from Jan 30 to Feb 01.

ASSISTANT: Ok,  please let me know the timing so  your journey.

USER: I am comfortable with any time.

ASSISTANT: Do you prefer any specific class to travel?

USER: No.

ASSISTANT: Do you have any more specifications?

USER: I need a direct flight ticket.

ASSISTANT: Can I have your good name please?

USER: My name is Thomas White.

ASSISTANT: Sorry to inform you that  no flight is available to you on your dates.

USER: Ok, that's not a problem. Thank you.

ASSISTANT: Thank you for choosing us, have a good day.