You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you today?

USER: Myself Lisa Phillips. I want to travel from DCA to LAS to attend my business meeting. Will you please help me in booking my ticket?

ASSISTANT: Sure, can I know your travel dates?

USER: My travelling dates are 03/31 to 03/02.

ASSISTANT: Please allow me a moment to check for the availability of flight.

USER: Ok.

ASSISTANT: Lisa, I am sorry to inform you that there is no flight available at your request.

USER: No issue. Thank you.

ASSISTANT: You are welcome. Thank you for contacting us.