You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Can you please help me in booking a flight ticket to IAD from EWR?

ASSISTANT: Sure, please share your planned travel dates?

USER: My planned travel dates are from Jul 16 to Jul 18.

ASSISTANT: Do you have any connection limit?

USER: I need a direct flight.

ASSISTANT: Any other preferences?

USER: No.

ASSISTANT: Can I have your name please?

USER: I am Katherine Anderson.

ASSISTANT: Sorry, no flights found with your given details.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for opting us.