ASP.NET - How to send the message to all login user in asp.net

Asked By Tahir khan on 19-Feb-13 05:18 AM
I have to create a utility to send the message to all user who are login and display the timer of 5 min then  forcefully logout-

i am calling the master page in each pages to can i display the message in master page will it be visible to all user or any plugins to send the message to login users ??