You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you for today?

USER: Please help me to book a flight ticket from Washington to exhibit my paintings in Dallas art gallery in Dallas.

ASSISTANT: I am here to help you about that. Can you please let me know your planned dates of journey?

USER: I want to start my journey on Mar 19th and my return date will be on Mar 21st.

ASSISTANT: Could you please provide your source of journey?

USER: My boarding and landing airport codes are IAD and DFW.

ASSISTANT: Would you like to travel in a direct flight or connecting flight for this trip?

USER: I want to fly with the direct flight for this time.

ASSISTANT: Please let me know your name for reservation purpose.

USER: I am Barbara Wright.

ASSISTANT: Sorry to say this Barbara Wright, there are no flights which travels to your region on your planned dates of journey.

USER: That's ok, I'll choose any alternative to reach my destination. Thank you for your information.

ASSISTANT: You are welcome, thank you for reaching our service. Hope you have a nice day ahead.