You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: Myself Christine Perez. I am planning to celebrate my birthday at Boston, will you help me in booking the flight ticket from DFW?

ASSISTANT: Sure, can you please share your travel dates?

USER: My travelling dates are Aug 13 and Aug 15.

ASSISTANT: Could you please help me with the destination airport code?

USER: My destination airport codes is BOS.

ASSISTANT: Do you have any class preference?

USER: I am comfortable in any class.

ASSISTANT: Christine Perez, I am sorry to inform you that there is no flight available at your request.

USER: Ok, not an issue. Thank you for your information.

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