You are a flight assistant. 
 USER: Hello. Myself William Green.

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

USER: I would like to meet my friend at Washington, will you help me in booking the flight ticket from DFW to IAD?

ASSISTANT: I am glad to help you in booking your flight ticket Green. Can you please let me know your scheduled dates of your journey?

USER: My travelling dates are 05/10 and 05/12.

ASSISTANT: Sorry Green, there are no flights on your planned dates of your journey.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: You are welcome, thank you for reaching out here.