CSS (just an example, duh)
  img#thumbnail {\
        display: none;\
        position: fixed;\
        right: 10px;\
        top: 35px;\
        max-width: 380px;\
        max-height: 200;\
        border-shadow: black 0 0 15px;\
        opacity: .7;\
      }\
      img#thumbnail:hover{\
          opacity: 1;\
      }\


var img = document.createElement('img');
    img.id = 'thumbnail';
    document.body.appendChild(img);

    var finput = $('input[name="upfile"]');
    finput.addEventListener('change', function(e) {
        var f = e.target.files[0];
        //console.log('File changed, new file: '+f.name);
        if (!f) {
            $('img#thumbnail').style.display = 'none';
            return;
        }
        var r = new FileReader();
        r.onload = function(e) {
            $('img#thumbnail').src = e.target.result;
            $('img#thumbnail').style.display = 'block';
        }
        r.readAsDataURL(f);
    }, false);