You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you please help me to reserve the flight ticket from PHL to BOS?

ASSISTANT: Sure, I will help you. Can I know your travel dates please?

USER: The planned travel dates are May 19 and May 21.

ASSISTANT: Ok, do you have any concern about the connection limit?

USER: Yes, I am looking for a single connecting flight.

ASSISTANT: Ok, may I know your name please?

USER: My name is Virginia Harris.

ASSISTANT: Sorry to tell you, there are no flights found with your travel dates.

USER: It's ok, not a problem with that. Thank you for searching the flights.

ASSISTANT: You are welcome. Thank you for choosing us.