You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I oblige you today?

USER: I am Rachel Roberts. I want to meet my friends at Washington, can you please help me to book a ticket?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Help me with the source and destination airport codes?

USER: DEN is my source airport and DCA is my destination.

ASSISTANT: May I know when you are willing to travel?

USER: I would like to leave between 01/19 and 01/21.

ASSISTANT: Do you have any other specifications?

USER: I need a halt.

ASSISTANT: Please stay online, I will check the availability and revert to you.

USER: Ok.

ASSISTANT: We found 1023 Southwest airlines with single connection with price 100. Shall I proceed with the booking?

USER: Ok, please book this ticket.

ASSISTANT: Your, booking has been confirmed.

USER: Thank you so much.

ASSISTANT: Thank you for reaching us.