I've been working on a large website project, and I upgraded the website to html5 and css3, while the problem goes to supporting IE6-IE8 which needs a lot of hacks and debugging, using HTML5Shiv, CSS3pie, Modernizr Selectivizr and many other browser polyfills, which is a great deal of time.
And the fact of the huge count down of the usage percent of those versions of IE which is about 0.1%-IE6 0.6%-IE7 4.6%-IE8 which is all about 5.3% and the percentage is still going down. In addition to the fact that soon Microsoft will drop down support for Windows XP on 2014, which is few months from now, sounds like a big waste of time and energy for such a huge project.
So like any web developer that want to provide the best environment experience for the audience I was Thinking and looking for the best way to provide IE6-IE8 users a way through a clean informative easy and convenience short way to show them a message that provides to download the latest version of other web browsers. So I've found this two JavaScript built solutions ie6-upgrade-warning and sevenup on code.google.com that carry the same idea but both only targeted for IE6 only, and I'm quite a beginner in JavaScript.
Is there anyway to add this functionality to include IE7 & IE8 in the javaScript file of sevenup for example? or any other solutions for this purpose that I don't know of like a hosted JS widget I might be able to use to accomplish this?