You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Can I know your name?

USER: I am Dorothy Campbell.

ASSISTANT: How can I serve you?

USER: Can you please book me a ticket with the fare of 500?

ASSISTANT: Sure, Please share me your travelling dates.

USER: I would like to leave between 03/17 and 03/19.

ASSISTANT: May I Know your airport codes?

USER: My travelling airport codes are from EWR to DCA.

ASSISTANT: We found a direct flight.

USER: Don't proceed for booking. I need a halt.

ASSISTANT: Ok. Thank you for contating us.