diff --git a/doc/README_zh.md b/doc/README_zh.md
index cc3b6ff..aadf3d0 100644
--- a/doc/README_zh.md
+++ b/doc/README_zh.md
@@ -94,7 +94,7 @@ if(os.platform()=="windows")
 ## __教程__
 
 Nasal是非常容易上手的，你甚至可以在15分钟之内看完这里的基本教程并且直接开始编写你想要的程序。
-__如果你先前已经是C/C++,javascript选手，那么这个教程几乎可以不用看了……__ 在看完该教程之后，基本上你就完全掌握了这个语言:
+__如果你先前已经是C/C++, javascript选手，那么几乎可以不用看这个教程……__ 在看完该教程之后，基本上你就完全掌握了这个语言:
 
 <details><summary>基本类型</summary>
 
diff --git a/doc/benchmark.md b/doc/benchmark.md
index 59580e4..da0f094 100644
--- a/doc/benchmark.md
+++ b/doc/benchmark.md
@@ -1,6 +1,6 @@
 # __Benchmark__
 
-![benchmark](../pic/benchmark.png)
+![benchmark](../doc/pic/benchmark.png)
 
 ## version 6.5 (i5-8250U windows10 2021/6/19)
 
@@ -109,4 +109,4 @@ And we use this bf interpreter to draw a mandelbrot set.
 
 In 2022/2/17 update we added `\e` into the lexer. And the `bfcolored.nas` uses this special ASCII code. Here is the result:
 
-![mandelbrot](../pic/mandelbrot.png)
+![mandelbrot](../doc/pic/mandelbrot.png)
diff --git a/doc/nasal-http-test-web.html b/doc/nasal-http-test-web.html
index 7b4d582..7532e25 100644
--- a/doc/nasal-http-test-web.html
+++ b/doc/nasal-http-test-web.html
@@ -60,8 +60,8 @@
             </p>
         </text>
         <h2>&nbsp;Benchmark | 执行效率</h2>
-        <img src="/pic/benchmark.png" width="450" height="350"></img>
-        <img src="/pic/mandelbrot.png" width="450" height="350"><br /></img>
+        <img src="/doc/pic/benchmark.png" width="450" height="350"></img>
+        <img src="/doc/pic/mandelbrot.png" width="450" height="350"><br /></img>
         <text>
             <p>
                 Benchmark of different versions of nasal interpreter(left).
diff --git a/pic/benchmark.png b/doc/pic/benchmark.png
similarity index 100%
rename from pic/benchmark.png
rename to doc/pic/benchmark.png
diff --git a/pic/favicon.ico b/doc/pic/favicon.ico
similarity index 100%
rename from pic/favicon.ico
rename to doc/pic/favicon.ico
diff --git a/pic/mandelbrot.png b/doc/pic/mandelbrot.png
similarity index 100%
rename from pic/mandelbrot.png
rename to doc/pic/mandelbrot.png
diff --git a/pic/nasal.png b/doc/pic/nasal.png
similarity index 100%
rename from pic/nasal.png
rename to doc/pic/nasal.png
diff --git a/nasal_codegen.h b/nasal_codegen.h
index c98964a..f3f627d 100644
--- a/nasal_codegen.h
+++ b/nasal_codegen.h
@@ -7,7 +7,7 @@
 #include <stack>
 #include <unordered_map>
 
-enum op_code:u8
+enum op_code_type:u8
 {
     op_exit,   // stop the virtual machine
     op_intg,   // global scope size
@@ -487,7 +487,7 @@ void nasal_codegen::call_id(const nasal_ast& ast)
         {
             gen(op_callb,i,ast.line());
             if(local.empty())
-                die("should warp native functions in local scope",ast.line(),ast.col());
+                die("should warp native function in local scope",ast.line(),ast.col());
             return;
         }
     i32 index;
diff --git a/test/httptest.nas b/test/httptest.nas
index 3d56fdd..97fd283 100644
--- a/test/httptest.nas
+++ b/test/httptest.nas
@@ -308,10 +308,10 @@ while(1){
             break;
         }
         elsif(path=="/favicon.ico")
-            http.send(client,respond.ok(io.fin("./pic/favicon.ico")));
+            http.send(client,respond.ok(io.fin("./doc/pic/favicon.ico")));
         elsif(path=="/license")
             http.send(client,respond.ok(io.fin("./LICENSE")));
-        elsif(path=="/pic/nasal.png" or path=="/pic/benchmark.png" or path=="/pic/mandelbrot.png")
+        elsif(path=="/doc/pic/nasal.png" or path=="/doc/pic/benchmark.png" or path=="/doc/pic/mandelbrot.png")
             http.send(client,respond.ok(io.fin("."~path)));
         else{
             var filename=substr(path,1,size(path)-1);