You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you?

USER: I am George Miller from Boston. I need to attend for a seminar on social issues in PHX. Can you please help me to book a flight from BOS?

ASSISTANT: Sure, please provide your depart and return dates.

USER: Sure, I want to depart on Sept 19 and need to return on Sept 21.

ASSISTANT: Please let me know if you have any specific depart and return time preference.

USER: My depart time must be in the afternoon and return time in the morning.

ASSISTANT: Do you prefer either economy or business class?

USER: I am comfortable with any class.

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

USER: I prefer to travel in a connecting flight.

ASSISTANT: Sorry, we don't have any flight available which meets all your requirement.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you.