You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please reserve a plane ticket from Washington to reach Las Vegas? Because I have to attend my final examination.

ASSISTANT: Sure, can I know your travelling dates?

USER: Thank you. My planned travel dates are Feb 03 and Feb 05.

ASSISTANT: Ok, let me know your source and destination airport codes?

USER: The source and destination airport codes are IAD and LAS.

ASSISTANT: Can I know your name?

USER: My name is Stephen Clark.

ASSISTANT: Do you have any specifications?

USER: I prefer a connecting flight.

ASSISTANT: Sorry, there are no flights found on given dates.

USER: It's ok, not a problem with that. Thank you for searching the flights.

ASSISTANT: Thank you for reaching us.