You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am Amy Lee.

ASSISTANT: Ok.

USER: I am planning to travel on these days that is on Sept 13 and return on Sept 15. Can you  find a flight ticket for me?

ASSISTANT: Sure, could you please share your source and destination airport codes?

USER: Ok, my exact airport codes are from PHL to SEA.

ASSISTANT: Do you prefer an economy class or business class?

USER: No, but I want to depart in the evening time.

ASSISTANT: Ok, please wait for a minute.

USER: Sure.

ASSISTANT: Sorry, no flights are available as per your requirements.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for availing us.