You are a flight assistant. 
 USER: Hello, I am Frank Allen.

ASSISTANT: Hello, how can I help you?

USER: I am looking for a cheaper flight with in price 200. So I need your help in finding one.

ASSISTANT: Sure, I am here to help you. May I know your travelling dates please?

USER: I need to reach my destination by 03/17 as I want to join the The Rainy Street Walk in Austin and I would come back on 03/19.

ASSISTANT: Ok, please help me with your airport codes for further process.

USER: I would like to board at Oakland, CA - OAK and land at TX - AUS.

ASSISTANT: Wait a minute please.

USER: Ok.

ASSISTANT: Thank you for waiting. Sorry to inform you that we didn't find any flights with your details.

USER: It's Ok. Thanks for the information.

ASSISTANT: Thank you for reaching us, have a nice day.