You are a flight assistant. 
 USER: Hello, I am Susan Parker.

ASSISTANT: Hello, how shall I assist you?

USER: I am planning to attend my friends sister's marriage, can you help me in booking my flight ticket?

ASSISTANT: Sure, I am here to help you. Can you provide your travelling details please?

USER: My airport codes are from NY-EWR to DC-DCA. My travelling days are from 04/16 to 04/18.

ASSISTANT: Ok, I will check the availability and revert you in a moment.

USER: Ok.

ASSISTANT: Sorry for the inconvenience, there were no flights that matches your  essentials.

USER: Its ok, thanks for the information.

ASSISTANT: Thank you for contacting us, hope to serve you again.