<script type="text/javascript">

        //need to wait until onload so body is available

        window.onload = function(){

            function getWindowWidth(){

                if (window.innerWidth){

                    return window.innerWidth;

                } else if (document.documentElement.clientWidth){

                    return document.documentElement.clientWidth;

                } else if (document.body.clientWidth){

                    return document.body.clientWidth;

                }

            }

            //determine if the browser has Netscape-style plugins

            var hasNSPlugins = !!(navigator.plugins && navigator.plugins.length);

            //determine if the browser has basic DOM Level 1 capabilities

            var hasDOM1 = !!(document.getElementById && document.createElement &&

                           document.getElementsByTagName);

            alert("Window width: " + getWindowWidth());

            alert("Supports Netscape plugins? " + hasNSPlugins);

            alert("Supports Core DOM 1?

" + hasDOM1);

        }

    </script>