diff --git a/build.conf b/build.conf
index 048df6323..6c0b3e322 100644
--- a/build.conf
+++ b/build.conf
@@ -1,2 +1,2 @@
 wechat_v="0.14.140900"
-nwjs_v="0.21.3"
+nwjs_v="0.19.4"
diff --git a/build.sh b/build.sh
index b5ded5e06..bc731916f 100755
--- a/build.sh
+++ b/build.sh
@@ -1,34 +1,36 @@
 #! /bin/sh
 # tar wechat-dev-tools
 
-. ./build.conf
-package_dir="./package.nw"
-tmp_dir="./.tmp"
-dist_dir="./dist"
-build_dir="./.build"
-nwjs_file="nwjs-v$nwjs_v.tar.gz"
-nwjs_dir="nwjs-sdk-v${nwjs_v}-linux-x64"
+cur_dir=`dirname $0`
+. "$cur_dir/build.conf"
+package_dir="$cur_dir/package.nw"
+tmp_dir="$cur_dir/.tmp"
+build_dir="$cur_dir/dist"
+
+nwjs_file="$tmp_dir/nwjs-v$nwjs_v.tar.gz"
+nwjs_dir="$tmp_dir/nwjs-sdk-v${nwjs_v}-linux-x64"
 nwjs_download="https://dl.nwjs.io/v$nwjs_v/nwjs-sdk-v${nwjs_v}-linux-x64.tar.gz"
 
-dist_wechat_dir="wechat-dev-tools"
-dist_wechat_package="wechat-v${wechat_v}-nwjs-v${nwjs_v}.tar.gz"
+dist_wechat_dir="$tmp_dir/wechat-dev-tools"
+dist_wechat_package="$tmp_dir/wechat-v${wechat_v}-nwjs-v${nwjs_v}.tar.gz"
+
 mkdir -p $tmp_dir
-if [ ! -d "$tmp_dir/$nwjs_dir" ]; then
-  if [ ! -f "$tmp_dir/$nwjs_file" ]; then
-    wget "$nwjs_download" -O .tmp/$nwjs_file
-    $? -ne 0 && exit $?
+if [ ! -d "$nwjs_dir" ]; then
+  if [ ! -f "$nwjs_file" ]; then
+    wget "$nwjs_download" -O $nwjs_file
+    $? -ne 0 && exit "$?"
   fi
 
-  tar -xf $tmp_dir/$nwjs_file -C $tmp_dir
-  $? -ne 0 && exit $?
+  tar -xf $nwjs_file -C $tmp_dir
+  $? -ne 0 && exit "$?"
 fi
 
-rm -rf $dist_dir
-mkdir -p $dist_dir/$dist_wechat_dir
-cp -rl "$tmp_dir/$nwjs_dir"/* "$dist_dir/$dist_wechat_dir" &&
-cp -rl "$package_dir" "$dist_dir/$dist_wechat_dir" &&
-tar -zcvf "$dist_dir/$dist_wechat_package" "$dist_dir/$dist_wechat_dir"
+rm -rf $dist_wechat_dir
+mkdir -p $dist_wechat_dir
+cp -rl "$nwjs_dir"/* "$dist_wechat_dir" &&
+cp -rl "$package_dir" "$dist_wechat_dir" &&
+tar -zcvf "$dist_wechat_package" "$dist_wechat_dir"
 
 mkdir -p $build_dir
-cp -l "$dist_dir/$dist_wechat_package" "$build_dir"
+mv -f "$dist_wechat_package" "$build_dir"