How to get status of the user (online,offline,away)

Question

How to get status of the user like online, offline or away(inactive for some time) in  C#?

 

I want to display the status of a user.If the user will be online then I have to show green icon on the user profile.If a user will be offline then I have to show grey icon and it might be possible that user will be logged in but not active in that case I have to display orange icon(for the idle user) on the profile.

 

I have to implement this feature in kentico.

 

Thanks in Advance

satyam