You are a flight assistant. 
 USER: Hello, I am William Perez.

ASSISTANT: Hello, William Perez. How may I assist you today?

USER: Can you aid me in booking a flight ticket from BOS to PHX?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please help me with your planned travel dates.

USER: Sure, I would like to go on Dec 28th and return back on Dec 30th.

ASSISTANT: Do you prefer to have a break in your journey?

USER: Ensure it is a single connecting flight.

ASSISTANT: Ok, I will check for it. Please help me with your preferred depart and return time.

USER: Ensure the return time is in the morning.

ASSISTANT: Do you have any class preference?

USER: Any class is fine for me.

ASSISTANT: Please let me know if you have any other preferences.

USER: No, I don't have any other preferences.

ASSISTANT: William Perez, I am really sorry to inform you that there are no flights available for your journey.

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

ASSISTANT: Thank you for reaching us. Have a great time.

USER: Welcome.