You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you today?

USER: I am Robert Lee, can you help me to book a direct flight for me?

ASSISTANT: Sure, can I know your trip dates please?

USER: I am planning to travel in this week, my journey dates are 10/11 and 10/13.

ASSISTANT: Ok, let me know your source and destination locations please.

USER: Sure, my preferred source and destination airport codes are JFK and AUS.

ASSISTANT: Ok, please wait for a while, I will let you know the availability.

USER: Sure, my price limit is 500.

ASSISTANT: Sorry to inform you, there is no flight available on your provided dates.

USER: Ok, no issues. Thank you for your help in searching.

ASSISTANT: You are welcome, have a nice day.