// the more standards compliant browsers (mozilla/netscape/opera/IE7) use window.innerWidth and window.innerHeight
         function getViewPortWidth() {

           var viewportwidth;
           var viewportheight;

              // the more standards compliant browsers (mozilla/netscape/opera/IE7) use window.innerWidth and window.innerHeight
             if (typeof window.innerWidth != 'undefined')
             {
                  viewportwidth = window.innerWidth,
                  viewportheight = window.innerHeight
             }

            // IE6 in standards compliant mode (i.e. with a valid doctype as the first line in the document)

             else if (typeof document.documentElement != 'undefined'
                 && typeof document.documentElement.clientWidth !=
                 'undefined' && document.documentElement.clientWidth != 0)
             {
                   viewportwidth = document.documentElement.clientWidth,
                   viewportheight = document.documentElement.clientHeight
             }

             // older versions of IE

             else
             {
                   viewportwidth = document.getElementsByTagName('body')[0].clientWidth,
                   viewportheight = document.getElementsByTagName('body')[0].clientHeight
             }

            return viewportwidth;
         }

                  function getViewPortHeight() {

           var viewportwidth;
           var viewportheight;

              // the more standards compliant browsers (mozilla/netscape/opera/IE7) use window.innerWidth and window.innerHeight
             if (typeof window.innerWidth != 'undefined')
             {
                  viewportwidth = window.innerWidth,
                  viewportheight = window.innerHeight
             }

            // IE6 in standards compliant mode (i.e. with a valid doctype as the first line in the document)

             else if (typeof document.documentElement != 'undefined'
                 && typeof document.documentElement.clientWidth !=
                 'undefined' && document.documentElement.clientWidth != 0)
             {
                   viewportwidth = document.documentElement.clientWidth,
                   viewportheight = document.documentElement.clientHeight
             }

             // older versions of IE

             else
             {
                   viewportwidth = document.getElementsByTagName('body')[0].clientWidth,
                   viewportheight = document.getElementsByTagName('body')[0].clientHeight
             }
            return viewportheight;
         }