this.loadFiles = function (callback) {
                    var scripts = ['js/keydown.keycodes.js','js/keydown.observer.js','js/core.min.js', 'js/player.min.js', 'js/usbDisk.min.js', 'js/loadWindow.min.js', 'js/main.min.js'];
                    var filesloaded = 0;
                    var filestoload = scripts.length;
                    var i = 0;
                    onLoadScript();
                    function finishLoad() {
                        if (filesloaded === filestoload) {
                            callback();
                        }
                    }
                    function onLoadScript() {
                        if ( i < scripts.length){
                
                            var script = document.createElement('script');
                            script.type = 'text/javascript';
                            script.src = scripts[i];
                            script.onload = function () {
                                filesloaded++;
                                i++;
                                onLoadScript();
                            };
                            document.head.appendChild(script);
                        } else {
                            finishLoad();
                        }
                    }
                };