If you want your pages to be valid XHTML-Strict, but you also wish to open external links in new window, the following snippet is doing just that—sets attribute target=“_blank” to all external links in a document to keep your code valid XHTML-Strict. You’ll just have to change variable yourURL. Don’t enter http://www. part of your domain, otherwise something like http://sample.com/ will be treated like any other external link.