You are a flight assistant. 
 USER: Hi,. This is Alexander Hernandez, from Washington.

ASSISTANT: Hello, how may I serve you today?

USER:  I want to book a flight ticket to meet my uncle in Las Vegas, will you help me in booking a flight ticket with a price limit of 5000?

ASSISTANT: Sure, may I know your trip dates?

USER: I want to travel on 04/15, and need to catch return flight on 04/17.

ASSISTANT: Could you help me with your airport codes?

USER:  I need to leave from my nearest airport DCA to reach LAS.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: We found a flight on Jetblue airline, flight number as 1017 with the fare of 100. Shall I proceed for booking?

USER: Proceed with the booking.

ASSISTANT: Your ticket has been booked.

USER: Thanks for the service.

ASSISTANT: Thank you for reaching us.