php image upload method

public function lbt() {        
        $ajax = input::get('ajax','');
        if($ajax == '1'){
             if(!empty($_FILES)){ 
                $fileDir = public_path().'/test/';
                $newFile = $fileDir.$_FILES["myfile"]["name"];
                $info = pathinfo($newFile);
                $type =  isset($info['extension']) ? $info['extension'] : false;
                $allowFiles = array('jpg', 'png', 'gif', 'mp3', 'mp4', 'wav', 'flv');
                if(!$type || !in_array($type, $allowFiles)){
                    echo '文件拓展名不对';
                }
                if($_FILES["myfile"]["error"] == 0){ 
                    move_uploaded_file($_FILES["myfile"]["tmp_name"], $newFile); 
                } 
                $data['url'] = url('test/'.$_FILES['myfile']['name']);
                $imgModel = new ImgModel();
                $imgModel->img_name = Input::get('name','');
                $imgModel->img_path = $_FILES['myfile']['name'];
                $imgModel->img_content = '';
                $imgModel->save();
              
            }