diff --git a/contact-center/admin/build.sh b/contact-center/admin/build.sh
index 7677df04..87396530 100755
--- a/contact-center/admin/build.sh
+++ b/contact-center/admin/build.sh
@@ -6,7 +6,7 @@
 # constants
 baseDir=$(cd `dirname "$0"`;pwd)
 appHome=$baseDir/..
-registryName=dockerhub.qingcloud.com
+registryPrefix=
 imagename=chatopera/contact-center
 TIMESTAMP=`date "+%Y%m%d.%H%M%S"`
 
@@ -16,6 +16,10 @@ TIMESTAMP=`date "+%Y%m%d.%H%M%S"`
 [ -z "${BASH_SOURCE[0]}" -o "${BASH_SOURCE[0]}" = "$0" ] || return
 # build
 cd $appHome
+if [ -d ../private ]; then
+    registryPrefix=dockerhub.qingcloud.com/
+fi
+
 PACKAGE_VERSION=`git rev-parse --short HEAD`
 
 set -x
@@ -29,10 +33,10 @@ docker build --build-arg VCS_REF=$PACKAGE_VERSION \
     --build-arg APPLICATION_BUILD_DATESTR=$TIMESTAMP \
     --build-arg APPLICATION_CUSTOMER_ENTITY=$APPLICATION_CUSTOMER_ENTITY \
     --no-cache \
-    --force-rm=true --tag $registryName/$imagename:$PACKAGE_VERSION .
+    --force-rm=true --tag $registryPrefix$imagename:$PACKAGE_VERSION .
 
 if [ $? -eq 0 ]; then
-    docker tag $registryName/$imagename:$PACKAGE_VERSION $registryName/$imagename:develop
+    docker tag $registryPrefix$imagename:$PACKAGE_VERSION $registryPrefix$imagename:develop
 else 
     echo "Build contact-center failure."
     exit 1
diff --git a/sample.env b/sample.env
index 633fc19c..6aa9ed36 100644
--- a/sample.env
+++ b/sample.env
@@ -1,5 +1,8 @@
 # https://docs.docker.com/compose/reference/envvars/#compose_file
-# for Enterprise edition: docker-compose.yml:./private/docker-compose.ext.yml
+# use Enterprise edition: docker-compose.yml:./private/docker-compose.ext.yml
+# use other customize yml, copy docker-compose.yml as docker-compose.custom.yml
+# and edit .env with COMPOSE_FILE=docker-compose.custom.yml, docker-compose.custom.yml
+# is ignored with .gitignore
 COMPOSE_FILE=docker-compose.yml
 COMPOSE_PROJECT_NAME=cskefu