You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Eric Green.

ASSISTANT: How may I help you?

USER: I have a business meeting in my head office which is in Boston, can you please help me in booking a flight ticket?

ASSISTANT: Sure, I will help you out.

USER: Thank you.

ASSISTANT: May I know your travelling dates please?

USER: The preferred travel dates are 05/04 and 05/06.

ASSISTANT: Can I know your airport codes too?

USER: My travelling airport codes are from DCA to BOS.

ASSISTANT: Ok, please wait a moment.

USER: Ok, please make sure that the connection limit is 0.

ASSISTANT: Sorry, there are no flights found.

USER: That's fine, thank you so much for your help.

ASSISTANT: Thank you for choosing us.

USER: Welcome.