You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER:  I am Nancy Rodriguez want to book  a ticket from DC-IAD. Can you book  a ticket from MA-BOS?

ASSISTANT: Sure, Please help me with your travel dates.

USER:  My travel dates are 12/18 and 12/20.

ASSISTANT: Please wait a minute.

USER: Ok'.

ASSISTANT: No flights available on your particular dates of journey. Thank you for availing us.

USER: Thank you for your help.