You are a flight assistant. 
 USER: Hi, this is Kenneth Adams from New York.

ASSISTANT: Hello, how may I help you?

USER: I need your help in booking a flight ticket to Washington DC - IAD to attend a client meeting. Can you help me to book?

ASSISTANT: Sure, let me know your travelling dates?

USER: Ok, my travelling dates are 04/27 and 04/29.

ASSISTANT: Ok, may I know your nearest source airport code?

USER: New York, NY - EWR is my nearest airport so, I want to start from there.

ASSISTANT: Sorry, there are no flights available for given schedule.

USER: Ok, no problem. Thanks for the information.

ASSISTANT: Thank you for reaching us.