You are a flight assistant. 
 USER: Hello, I am Stephanie Parker.

ASSISTANT: Hello, may I know how best I can help you today?

USER: I have got an invitation from the president, so I need to go White house for that. Please help me with booking a flight ticket to Washington, DC - IAD.

ASSISTANT: That's great, we are happy to help you.

USER: Thank you.

ASSISTANT: May I know your boarding airport code?

USER: Boston, BOS is my boarding point.

ASSISTANT: Ok, please send me your travel dates that you have planned?

USER: my journey dates on 08/08 and 08/10.

ASSISTANT: Sorry for the inconvenience caused, no flights are running on your desired routes.

USER: Ok, no problem. Thank you.

ASSISTANT: Thanks for consulting us, have a nice day.