You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: My name is Mark Walker. I am looking to book a flight ticket to attend my brother's marriage in Washington can you help me for booking a flight ticket from EWR to IAD?

ASSISTANT: Sure, I will help you in booking. May I know your planned travel dates?

USER: My travelling dates are 06/30 and 0702.

ASSISTANT: Ok, please allow me a moment to check for the flight availability.

USER: Sure, I will wait for your response.

ASSISTANT: Thank you for waiting. Sorry to say , there are no flights available for your desired dates.

USER: That's ok, thank you for checking. Welcome.

ASSISTANT: Thank you for opting us.