You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Michelle Robinson. As I am a scientist, I want to research on Rockets in NASA Space Center at Houston, IAH. Can you please book a ticket from BOS?

ASSISTANT: Sure, can I know your travelling dates?

USER: My travelling dates are Aug 14 and Aug 16.

ASSISTANT: Ok, let me know your source airport code?

USER: I have already mentioned.

ASSISTANT: Do you have any particular time for departing and returning?

USER: My return time is afternoon.

ASSISTANT:  Would you like to prefer direct flight or connecting flight?

USER: I want single connection.

ASSISTANT: Which class do you prefer?

USER: I am comfortable with any class.

ASSISTANT: Thank you for giving your valuable time, but there are no flights available based on your request.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for opting us, we hope to serve you again with better features.