diff --git a/debian-add-user.sh b/debian-add-user.sh
index ac24bba..1a90f6c 100755
--- a/debian-add-user.sh
+++ b/debian-add-user.sh
@@ -30,7 +30,7 @@ sed -i "s|/home/$NewUser:$|/home/$NewUser:/bin/bash|g" /etc/passwd
 echo "<<< Allow the new user $NewUser to sudo without password"
 #usermod -a -G sudo $NewUser # Add to sudo group # Option 1: add user to %sudo group
 echo "$NewUser ALL=(ALL:ALL) NOPASSWD:ALL" > /etc/sudoers.d/${NewUser//./-} # Option 2: add a user file into /etc/sudoers.d/
-chmod a-w /etc/sudoers.d/$NewUser
+chmod a-w /etc/sudoers.d/${NewUser//./-}
 echo
 
 # 注意，在这里为新用户创建的配置文件，主人是 root，而不是新用户
diff --git a/docker-install.sh b/docker-install.sh
index 171cb89..8e50bcb 100755
--- a/docker-install.sh
+++ b/docker-install.sh
@@ -1,6 +1,6 @@
 # https://docs.docker.com/engine/install/debian/
 
-read -p "Choose docker source (a: 阿里云, z: 中科大) >> " DOCKER_SOURCE
+read -p "Choose docker source (a: 阿里云, z: 中科大, leave blank for default) >> " DOCKER_SOURCE
 if [ $DOCKER_SOURCE = 'a' ]
 then
   GPG_URL=http://mirrors.aliyun.com/docker-ce/linux/debian/gpg
@@ -54,4 +54,4 @@ then
   echo "    \"$DOCKER_MIRROR\"" | sudo tee -a /etc/docker/daemon.json > /dev/null
   echo "  ]" | sudo tee -a /etc/docker/daemon.json > /dev/null
   echo "}" | sudo tee -a /etc/docker/daemon.json > /dev/null
-fi
\ No newline at end of file
+fi