I'm sorry to ask a vague question, but I can't find the answer to this anywhere. I have a site that involves users. What I would like to know is if there is a code or some type of programming that would notify a user of a different user's action. For example, USER A adds content to one section of my site, and USER B gets a notification "pop-up" I call it while he is looking at any other page on the site, without reloading the page, just popping up right when it happens. Things like, "USER A has just logged on". Any help would be GREATLY appreciated!