Hello.
user
Hello. How can I help you today?
assistant
I am Donald Lee. I want to meet my business partner at Washington DC, please help me in booking my flight ticket from AUS to DCA.
user
Sure, I am here to help you in booking process. Can you please share  your travel dates?
assistant
Sure, I would like to start my journey on Aug 25th and also please book my return ticket on Aug 27th.
user
Do you have any airline preference?
assistant
No.
user
Do you have any other requirement?
assistant
I would like to depart in the afternoon.
user
Sorry, no flights are available on your particular travel dates.
assistant
Not an issue. Anyway, thank you for checking.
user
Thank you for opting us.
assistant