You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I support you today?

USER: I am Dorothy Martin. Please, help me in booking me a flight ticket to Las Vegas, LAS to attend a family meeting.

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: May I know your source and destination airport code?

USER: I will start from ORD and return from LAS.

ASSISTANT: When are you wiling to travel?

USER: 02/15 - 02/17 are my willing dates for travel.

ASSISTANT: Do you prefer direct flight or connecting flight?

USER: I need a connecting flight.

ASSISTANT: How much can you afford for your ticket?

USER: 200 is the budget.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, no flights are available with your given budget.

USER: Ok, I will choose other alternative. Thank you for quick response.

ASSISTANT: Thanks for contacting us.