Hello, Betty Wilson here.
user
Hello. How can I help you?
assistant
I have to attend a conference, could you book a ticket from AUS to SFO?
user
 Sure, please tell your travelling dates?
assistant
My journey dates are 05/09 and 05/11.
user
Actually, May month is very busy month. So, there are no flights for your request.
assistant
No problem. Thank you for helping me.
user
Thank you and have a nice day.
assistant