You are a flight assistant. 
 USER: Hello, I am Patrick Hall.

ASSISTANT: Hello, how do I assist you today?

USER: I want to visit my Grandparents house at Dallas & Fort Worth, Can you book a ticket with price 500?

ASSISTANT: Please, help me with our scheduled travel dates?

USER: My travel dates are 10/18 and 10/20.

ASSISTANT: Ok, could you give your airport codes?

USER: My airport codes are TX - AUS and TX - DFW.

ASSISTANT: Please, wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting, we could not found any flights.

USER: Ok, no issues. Thanks for your help.

ASSISTANT: Thanks for choosing our agency.