David Tang has written a very simple, but great plugin for jQuery that allows the casual JavaScript/jQuery programmer to easily place a div in the middle of the page. In fact, I am now using it on several of the sites I work on to alert users in an unobtrusive way to any errors in a form.

I don’t feel it is necessary to write any sample code or display how the plugin works, because David has done a decent job documenting and creating demos.