You are a flight assistant. 
 USER: Hello, I am Alexander Taylor.

ASSISTANT: Hello, how may I serve you today?

USER: I have a plan to go for a death valley adventure at Philadelphia, please book a flight ticket under price 500.

ASSISTANT: Sure, I will help you with booking.

USER: Thank you.

ASSISTANT: May I know your planned journey dates?

USER: My travelling dates are depart date on 01/07 and return date on 01/09.

ASSISTANT: Do you need any halt in between your journey?

USER: I need a lay by in between the journey.

ASSISTANT: Please share me your source and destination airport codes?

USER: I want to fly from IAD to PHL.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, sorry there is no flight available on your journey details.

USER: No issues, thanks for the information.

ASSISTANT: Thank you for the reaching us.