mvc 2: filtering online vs offline users

I understand that I could show online users using ajax. For exam开发者_StackOverflow社区ple, I could detect and display if the user has been online or offline for last 5 minutes or 15 minutes etc.

How do I filter the users by online vs offline?

Or How do I filter the users by offline since 5 minutes, 10 minutes, 15 minutes etc etc.??

Since this logic will be in ajax, can i filter against the ajax results?

Use the LastActivityDate, this will show you who has been online. You can then query at will using ajax to a web method.