You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am Joseph Young want to visit Boston, can you help me to book a direct flight?

ASSISTANT: Yes, I can help you. Can you share me your travelling dates?

USER: Sure, my travelling dates will be 11/18 and 11/20.

ASSISTANT: Ok, can you tell me your nearest airport codes?

USER: Yes, I want to fly from PHL to BOS.

ASSISTANT: Give me a moment.

USER: Ok.

ASSISTANT: Sorry to inform you that there are no flights found on your dates.

USER: That's ok, thank you.

ASSISTANT: Thank you for contacting us.