diff --git a/GenDHparam.sh b/GenDHparam.sh
index 0e29ab6..adb5693 100755
--- a/GenDHparam.sh
+++ b/GenDHparam.sh
@@ -1,5 +1,4 @@
 #!/bin/bash
 
 mkdir -p /etc/ssl/certs/
-[ -f /etc/ssl/certs/dhparam.pem ] && rm /etc/ssl/certs/dhparam.pem
-openssl dhparam -out /etc/ssl/certs/dhparam.pem 4096
+[ -f /etc/ssl/certs/dhparam.pem ] || openssl dhparam -out /etc/ssl/certs/dhparam.pem 4096
diff --git a/README.md b/README.md
index 733a21e..4782400 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,7 @@
-# Example Conf for Nginx multidomain reverse proxy 
+#Nginx Config
+
+A example config for nginx multidomain reverse proxy
+
+
+use `./GenDHparam.sh` to generate dhparam if not exist.
+This repo contain files for `/etc/nginx/`