Upload image and/or a file with Javascript

upload.js

         uploadImg: function(file, imgPreview, imgUrl) {
                var self = this

                console.log('file=', file)
                imgPreview.html('<i class="icon-spinner icon-spin"></i>')
                imgUrl.val('')

                reader = new FileReader();
                reader.onload = (function(tFile) {
                    return function(evt, response) {

                        var xhr = new XMLHttpRequest();
                        xhr.onreadystatechange = function(ev) {
                            if (xhr.readyState == 4 && xhr.status == 200) {

                                if (xhr.responseText.indexOf('ERROR') !== -1) {
                                    //  $('#picPreview').html(' ');
                                    imgPreview.html("<div class='alert'><button type='button' class='close' data-dismiss='alert'>&times;</button>" + xhr.responseText + "</div>");

                                } else {
                                    //   $("#settingsErrors").html(" ");
                                    console.log('evt=', evt)
                                    console.log('xhr', xhr)
                                    imgUrl.val(xhr.responseText)
                                    imgPreview.html('<img src="' + evt.target.result + '" /> ');

                                    // $('.usrProfilePicHolder').attr('src', evt.target.result);

                                    //  $('#settingsModal').modal('hide');

                                }

                            } else if (xhr.readyState == 4 && xhr.status == 413) {
                                imgPreview.html("<div class='alert'><button type='button' class='close' data-dismiss='alert'>&times;</button>File size too big!</div>");
                            } else if (xhr.readyState == 4 && xhr.status > 210) {
                                imgPreview.html("<div class='alert'><button type='button' class='close' data-dismiss='alert'>&times;</button>Error uploading file, try again :(</div>");
                            }

                        };
                        xhr.open('POST', '/uploadImg', true);
                        xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
                      
                        var data = '&type=' + file.type + '&file=' + encodeURIComponent(evt.target.result);
                        xhr.send(data);
                        // $("#settingsErrors").html("<div style='font-size:35px;color:white;'> <i class='icon-spinner icon-spin'> </i>  </div> ");

                    };
                }(file));
                reader.readAsDataURL(file);
            }

usage.js

var file = $('.fileInput').get(0).files[0];
if (!file) {
	$(.error').html("Unable to upload image").show()
	return;
}

var imgPreview = $('.imgPrev')
var imgUrl = $('.imgUrl')

this.uploadImg(file, imgPreview, imgUrl)