When use Virtual server admin web console, got error:
Message: 'document.getElementById(...)' is null or not an object
IE8 seems to have some trouble to work normally with the js controls of Virtual Server 2005, but you can easily make it work by choosing IE8 to work in IE7 compatibility mode.
Just aside to the url you should have a button that seems like a "broken sheet of paper". Click on that and you will be in IE7 compatibility mode, and everything will work fine with Virtual Server.