You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Patrick Wilson, can you please help me to book my flight ticket to DCA from LAX in the month of August to attend a workshop in DCA?

ASSISTANT: Sure, may I know your preferable travel dates please?

USER: Sure, my preferable travel dates are 08/17 and 08/19.

ASSISTANT: Please wait for a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there is a no flight available on your requested dates.

USER: Not a problem, I will go with another resources to reach out my destination point. Anyways thank you for the information.

ASSISTANT: Thank you approaching us.