You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, welcome to our agency. How may I help you today?

USER: Do you help me in booking round trip flight tickets?

ASSISTANT: Yes, I am here to help you. Before I start your reservation process, can I know your good name?

USER: My name is Anna Baker.

ASSISTANT: Baker, can you please provide me your airport codes for this round trip?

USER: My friends have planned a trip to Denver, all the way they are coming from their locations. Can you please search a flight from New York, NY-LGA to Denver, CO-DEN.

ASSISTANT: Noted, on which date you want to depart from LGA?

USER: I would like to depart from New York, LGA on 08/23.

ASSISTANT: Noted, do you want me to book your return ticket?

USER: Yes, I am planning to return on 08/25 from Denver.

ASSISTANT: Ok, please be on hold for a while. Let me check for the available flights.

USER: Sure, take your own time and find a flight ticket fare under 200.

ASSISTANT: Sorry Baker, there are no flights available on your preferred dates.

USER: Ok, not an issue. I will find any alternate for this trip. Anyway, thank you for your help in providing the valuable information.

ASSISTANT: Thank you very much for contacting and have a nice day.