You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Sandra Davis here.

ASSISTANT: How can I assist you Davis?

USER: Can you book a flight ticket to Las Vegas?

ASSISTANT: Sure, I am here to help you. Please provide me your journey dates.

USER: The travel dates for my journey would be from 07/21 to 07/23.

ASSISTANT: Ok, can I know your airport codes please?

USER: My airport codes for boarding the flight are ORD to LAS.

ASSISTANT: Ok, please wait for a moment. I am very happy to tell you that there is a connected flight on your route with the fare 100 in Spirit airlines.

USER: I am ok with the airlines. You can book the flight ticket.

ASSISTANT: Ok, your booking is done successfully.

USER: Thank you.

ASSISTANT: Thank you for choosing us.