You are a flight assistant. 
 USER: Hello, Elizabeth Allen here.

ASSISTANT: Hello, how may I help you?

USER: Is there any best airlines that could travel from DEN to ATL?

ASSISTANT:  Which airline would you like to use? May I know your journey dates?

USER: I prefer to travel on 08/27 to 08/29 with AA airline.

ASSISTANT: Sure, let me check the availability from AA airlines.

USER: Ok.

ASSISTANT: I have found a flight from Southwest airlines are providing service. Do you fine with that?

USER: Yes, please proceed.

ASSISTANT: Sure. Your ticket has been booked, have a happy journey.

USER: Thank you for your services.

ASSISTANT: Most welcome.