var win;
    
    function wopen(url, name, w, h, ignoreParams)
    {
        if(win){win.close()} // if window exists close it
        
        // Fudge factors for window decoration space.
        // In my tests these work well on all platforms & browsers.
        w += 32;
        h += 96;
        wleft = (screen.width - w) / 2;
        wtop = (screen.height - h) / 2;
        // IE5 and other old browsers might allow a window that is
        // partially offscreen or wider than the screen. Fix that.
        // (Newer browsers fix this for us, but let's be thorough.)
        if (wleft < 0) {
            w = screen.width;
            wleft = 0;
        }
        if (wtop < 0) {
            h = screen.height;
            wtop = 0;
          }
          
          if (ignoreParams)
            win = window.open(url,
                name,
                'width=' + w + ', height=' + h + ', ' +
                'left=' + wleft + ', top=' + wtop + ', ' +
                'location=yes, menubar=yes, ' +
                'status=yes, toolbar=yes, scrollbars=yes, resizable=yes, directories=yes');
          else
              win = window.open(url,
                name,
                'width=' + w + ', height=' + h + ', ' +
                'left=' + wleft + ', top=' + wtop + ', ' +
                'location=no, menubar=no, ' +
                'status=no, toolbar=no, scrollbars=no, resizable=yes, directories=no');
        
          // Just in case width and height are ignored
          win.resizeTo(w, h);
          // Just in case left and top are ignored
          win.moveTo(wleft, wtop);
          win.focus();
    }