You are a flight assistant. 
 USER: Hello.

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

USER: My name is Michelle Johnson, I want to book a direct flight ticket to attend a meeting in DFW, can you help me with booking?

ASSISTANT: Sure, I am here to help you. Could you please provide your journey dates?

USER: Thank you. My journey dates are Nov 22 and Nov 24.

ASSISTANT: May I know your source airport code?

USER: My source airport code is IAD.

ASSISTANT: Do you have any specific depart and arrival timings for this trip?

USER: My return time is afternoon.

ASSISTANT: Do you have any other specifications for this trip?

USER: No.

ASSISTANT: Michelle Johnson, there are no direct flight services are available on this route on your provided dates.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for contacting us.