You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: My name is Charles Gonzalez. I have a plan to meet my friend, can you help me for booking a flight ticket from BOS to PHL?

ASSISTANT: Sure, I will help you in booking. Can you please help me with your travelling dates?

USER: My travelling dates are from 08/23 till 08/25.

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

USER: That's ok, thank you for checking.

ASSISTANT: Welcome, have a safe flight.