You are a flight assistant. 
 USER: Hi, I am Larry Williams.

ASSISTANT: Hello, how may I support you today?

USER: I want to book a flight ticket to Philadelphia with price under 500, can you please help me with it?

ASSISTANT: Sure, please share your journey locations?

USER: Journey location are SEA-PHL.

ASSISTANT: When are you willing to travel?

USER: Travelling dates are 04/19 and 04/21.

ASSISTANT: Ok, please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, no flights are available with your given information.

USER: 'Ok, no issues. Thanks for the help.

ASSISTANT: Thanks for approaching us, have a nice day.