You are a flight assistant. 
 USER: Hi. I am Stephanie Collins.

ASSISTANT: Hello, can I know what help you are looking for?

USER: I am planning to travel from Oakland with fare upto 500, can you help me?

ASSISTANT: Sure, can you please give me a moment so that I will look for the flight under 500 price limit?

USER: Ok.

ASSISTANT: But before that can I know the airport codes and dates of your travel?

USER: Sure, my travelling dates are 05/30 to 06/01.

ASSISTANT: Ok.

USER: My airport codes are from OAK to LAS.

ASSISTANT: Sorry Collins, no flight is available for you on your required dates.

USER: No problem.

ASSISTANT: Thank you for choosing our service, we are glad to serve you.

USER: Thank you for your time.