You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I help you?

USER: I am Joshua Harris. I would like to attend a meeting in Old South Meeting House at Boston, BOS. Can you please book a flight ticket on 07/11?

ASSISTANT: Sure, please share me your return date?

USER: I would like to return back on 07/13.

ASSISTANT: Kindly assign me your source code?

USER: My source point is New  York, EWR.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there were no flights with you given details.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.