diff --git a/function/common.php b/function/common.php
index 973b410..35b7672 100644
--- a/function/common.php
+++ b/function/common.php
@@ -614,7 +614,20 @@ function main($path)
             } else return output(json_encode($exts['img']),400);
         } else return output('',401);
     }
+
     $files = list_files($path);
+    //echo json_encode(array_keys($files['children']), JSON_PRETTY_PRINT);
+    if (isset($_GET['random'])&&$_GET['random']!=='') {
+        if ($_SERVER['ishidden']<4) {
+            $tmp = [];
+            foreach (array_keys($files['children']) as $filename) {
+                if (strtolower(splitlast($filename,'.')[1])==strtolower($_GET['random'])) $tmp[$filename] = $files['children'][$filename]['@microsoft.graph.downloadUrl'];
+            }
+            $tmp = array_values($tmp);
+            if (count($tmp)>0) return output('', 302, [ 'Location' => $tmp[rand(0,count($tmp)-1)] ]);
+            else return output('',404);
+        } else return output('',401);
+    }
     if (isset($files['file']) && !$_GET['preview']) {
         // is file && not preview mode
         if ( $_SERVER['ishidden']<4 || (!!getConfig('downloadencrypt')&&$files['name']!=getConfig('passfile')) ) return output('', 302, [ 'Location' => $files['@microsoft.graph.downloadUrl'] ]);
@@ -927,6 +940,13 @@ function fetch_files($path = '/')
                     $files=fetch_files_children($files, $path1, $page);
                 } else {
                 // files num < 200 , then cache
+                    if (isset($files['children'])) {
+                        $tmp = [];
+                        foreach ($files['children'] as $file) {
+                            $tmp[$file['name']] = $file;
+                        }
+                        $files['children'] = $tmp;
+                    }
                     savecache('path_' . $path, $files);
                 }
             }
@@ -938,6 +958,7 @@ function fetch_files($path = '/')
             $files = json_decode( '{"unknownError":{ "stat":'.$arr['stat'].',"message":"'.$arr['body'].'"}}', true);
         }
     }
+
     return $files;
 }
 
diff --git a/readme.md b/readme.md
index 6de9882..689958b 100644
--- a/readme.md
+++ b/readme.md
@@ -1,5 +1,5 @@
-QQ Group: 943919989  
-Telegram Group: https://t.me/joinchat/I_RVc0bqxuxlT-d0cO7ozw  
+Install program first, then add onedrive in setup after login.  
+先安装程序，登录后在设置中添加onedrive。  
 
 # Deploy to heroku  
 Official: https://heroku.com  
@@ -20,13 +20,14 @@ How to Install:
     让代码中的config.php文件程序可读写，推荐chmod 666 config.php。  
     5.View the website in chrome or other.  
     在浏览器中访问。  
-    6.Follow the guide, bind your onedrive.  
-    根据引导，绑定你的OneDrive。  
 
 # Deploy to SCF  
 Official: https://cloud.tencent.com/product/scf  
 
-How to Install:  https://service-pgxgvop2-1258064400.ap-hongkong.apigateway.myqcloud.com/test/abcdef/%E6%97%A0%E6%9C%8D%E5%8A%A1%E5%99%A8%E5%87%BD%E6%95%B0SCF%E6%90%AD%E5%BB%BAOneDrive.mp4?preview  
+~~How to Install:  https://service-pgxgvop2-1258064400.ap-hongkong.apigateway.myqcloud.com/test/abcdef/%E6%97%A0%E6%9C%8D%E5%8A%A1%E5%99%A8%E5%87%BD%E6%95%B0SCF%E6%90%AD%E5%BB%BAOneDrive.mp4?preview~~  
+
+先在环境变量添加Region，ap-hongkong或ap-guangzhou之类，再安装。  
+添加网盘时，SCF反应不过来，会添加失败，请不要删除，再添加一次相同的就可以了。  
 
 DEMO:  https://service-pgxgvop2-1258064400.ap-hongkong.apigateway.myqcloud.com/test/abcdef/  
 
@@ -39,7 +40,7 @@ The XXX_path in setting is the path in Onedrive, not in url, program will find t
 设置中的 XXX_path 是Onedrive里面的路径，并不是你url里面的，程序会去你Onedrive里面找这个路径。  
 LOGO ICON: put your 'favicon.ico' in the path you showed, make sure xxxxx.com/favicon.ico can be visited.   
 网站图标：将favicon.ico文件放在你要展示的目录中，确保 xxxxx.com/favicon.ico 可以访问到。  
-Program will show content of 'readme.md' under file list.  
+Program will show content of 'readme.md' & 'head.md'.  
 可以在文件列表下面显示readme.md文件的内容。  
 guest up path, is a folder that the guest can upload files, but can not be list (exclude admin).  
 游客上传目录（也叫图床目录），是指定一个目录，让游客可以上传文件，不限格式，不限大小。这个目录里面的内容不列清单（除非管理登录）。  
@@ -48,3 +49,5 @@ If there is 'index.html' file, program will only show the content of 'index.html
 Click 'EditTime' or 'Size', the list will sort by time or size, Click 'File' can resume sort.  
 点击“时间”、“大小”，可以排序显示，点“文件”恢复原样。  
 
+QQ Group: 943919989  
+Telegram Group: https://t.me/joinchat/I_RVc0bqxuxlT-d0cO7ozw