Asp.net Folder Upload Control

<div id="dropzone"></div>

var dropzone = document.getElementById('dropzone');
dropzone.ondrop = function(e) {
  var length = e.dataTransfer.files.length;
  for (var i = 0; i < length; i++) {
    var file = e.dataTransfer.files[i];
    ... // do whatever you want
  }
};

<div id="dropzone"></div>

var dropzone = document.getElementById('dropzone');
dropzone.ondrop = function(e) {
  var length = e.dataTransfer.items.length;
  for (var i = 0; i < length; i++) {
    var entry = e.dataTransfer.items[i].webkitGetAsEntry();
    if (entry.isFile) {
      ... // do whatever you want
    } else if (entry.isDirectory) {
      ... // do whatever you want
    }
  }
};