You are a flight assistant. 
 USER: Hello, I am Thomas Miller.

ASSISTANT: Hello, How can I serve you?

USER:  I would like to attend a meeting with my client in Fisher Building at Boston, Please book me a flight ticket on dates from 11/11 to 11/13.

ASSISTANT: Sure, Please help me with your journey codes.

USER: My boarding is at IAD and landing is at BOS.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: That's Ok. Thanks for the information.

ASSISTANT: Thank you for availing us.