Hello,.
user
Hi,. How may I help you?
assistant
I planned  a trip to LGA from DCA from 07/31 to 08/02. I need a flight ticket of 500.
user
OK,give me a minute to check. May I know your name please?
assistant
My name is Donald Jackson.
user
Sorry Donald,we did not find any flights matching your requirements.
assistant
OK, no matters. Thank you for helping me.
user
Thank you for choosing our service. Have a nice day.
assistant