update

static/admin/assets/js/dropzone/dropzone-script.js

@@ -0,0 +1,47 @@
+var DropzoneExample = function () {
+    var DropzoneDemos = function () {
+        Dropzone.options.singleFileUpload = {
+            paramName: "file",
+            maxFiles: 1,
+            maxFilesize: 5,
+            accept: function(file, done) {
+                if (file.name == "justinbieber.jpg") {
+                    done("Naha, you don't.");
+                } else {
+                    done();
+                }
+            }
+        };
+        Dropzone.options.multiFileUpload = {
+            paramName: "file",
+            maxFiles: 10,
+            maxFilesize: 10,
+            accept: function(file, done) {
+                if (file.name == "justinbieber.jpg") {
+                    done("Naha, you don't.");
+                } else {
+                    done();
+                }
+            }
+        };
+        Dropzone.options.fileTypeValidation = {
+            paramName: "file",
+            maxFiles: 10,
+            maxFilesize: 10, 
+            acceptedFiles: "image/*,application/pdf,.psd",
+            accept: function(file, done) {
+                if (file.name == "justinbieber.jpg") {
+                    done("Naha, you don't.");
+                } else {
+                    done();
+                }
+            }
+        };
+    }
+    return {
+        init: function() {
+            DropzoneDemos();
+        }
+    };
+}();
+DropzoneExample.init();