You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am Melissa Taylor. Can you please help me to book a flight ticket from Philadelphia to Washington?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: Thank you. The preferable travel dates are Jan 25 and Jan 27.

ASSISTANT: Ok, may I know your location airport codes?

USER: My source and destination airport codes are PHL and DCA.

ASSISTANT: The Southwest airline with flight number 1011 is available having fare as 100 and connection as 1, is it ok for you?

USER: That's fine, please proceed with the ticket booking.

ASSISTANT: Ok, your reservation is confirmed.

USER: Thank you for helping me.

ASSISTANT: You are welcome, have a great day.