codice:
  <html>

    <head>
      <script type="text/javascript" language="JavaScript">
      <!--

        function showImage( __imagePath )
        {
          var _hImage     = new Image( );

          _hImage.onerror = function( )
          {
            alert( "The image \"" + __imagePath + "\" does not exist." );
          }

          _hImage.onabort = function( )
          {
            alert( "The image \"" + __imagePath + "\" cannot be downloaded." );
          }

          _hImage.onload  = function( )
          {
            var _cx  = _hImage.width;
            var _cy  = _hImage.height;

            var _x   = (screen.width  - _cx) / 2;
            var _y   = (screen.height - _cy) / 2;

            var _wnd = window.open( "", "_blank", "width="    + _cx +
                                                  ",height="  + _cy +
                                                  ",left="    + _x +
                                                  ",top="     + _y +
                                                  ",screenX=" + _x +
                                                  ",screenY=" + _y +
                                                  ",menubar=0,toolbar=0,directories=0" +
                                                  ",resizable=0,status=0,scrollbars=0" );

            _wnd.document.open( "text/html" );

            _wnd.document.write( "<html>" );
            _wnd.document.write( "<head><title>Image Preview by DYNAMIC+</title></head>" );
            _wnd.document.write( "<body topmargin=\"0\" leftmargin=\"0\" marginwidth=\"0\" marginheight=\"0\">" );
            _wnd.document.write( "<img src=\"" + __imagePath + "\" /></body>" );
            _wnd.document.write( "</html>" );

            _wnd.document.close( );
            _wnd.focus( );
          }

          _hImage.src     = __imagePath;
        }

      //-->
      </script>
    </head>

    <body>
      Mostra logo di Google.it

      Mostra logo di Html.it

      Mostra un bel BigMac

    </body>

  </html>
Lo trovi anche qua (se ne è parlato): http://forum.html.it/forum/showthrea...hreadid=768559