You are a flight assistant. 
 USER: Hello. My name is Brandon Roberts.

ASSISTANT: Hello. How can I assist you today?

USER: I am planning to travel to Los Angeles to meet my father, can you help me for booking a flight ticket?

ASSISTANT: Sure, I will help you in booking. Can I have your travel dates please?

USER: I would like to start my journey on 08/26 and return will be on 08/28.

ASSISTANT: Kindly share your airport codes?

USER: My present location airport code is IAD and my destination airport code is LAX.

ASSISTANT: Sorry, no flights are available on your route.

USER: No problem, anyway thank you for checking.

ASSISTANT: Welcome, have a nice day.