关于C++上的一些错误

我想编译一个php代码到dll，我是这个创建东西的新手，但我需要这个文件是dll。

以下是我需要编译到dll的代码：

#include "Stdafx.h"
#include "Post.h"
void DataSendAll(unsigned char* Packet, int Length)
{
for (int i=6400; i<7400; i++)
if(gObjIsConnected(i))
DataSend(i, Packet, Length);
}
void SendPost(int wId, LPCSTR Command, LPCSTR Text)
{
if (IsPost != 1) return;
if (!gObjIsConnected(wId)) return;
if (!strcmpi(Command, "/Post"))
{
MessageOutput(wId, "[%s] Useage: /Post <Msg>.", szPrefix);
MessageOutput(wId, "[%s] Price for post: %d, Minimun Level: %d", szPrefix, PostCost,
`PostLevel);
return;
}
gObj_SetInfo(wId);
if (gObj.Level < PostLevel)
{
MessageOutput(wId, "[%s] You're level is too low to post!", szPrefix);
return;
}
if (gObj.Money < PostCost)
{
MessageOutput(wId, "[%s] You don't have enough money to post!", szPrefix);
return;
}
BYTE *Packet;
char Message[100];
Packet = (BYTE*) malloc(200);
memset(Packet, 0x00, 200);
*Packet = 0xC1;
*(Packet+2) = 0x00;
memcpy((Packet+3), gObj.Nick, strlen(gObj.Nick));
sprintf(Message, "@@[Global] %s", Text);
memcpy((Packet+13), Message, strlen(Message));
int Len = (strlen(Message) + 0x13);
*(Packet+1) = Len;
DataSendAll(Packet, Len);
int Amount = (gObj.Money - PostCost);
gObj_Write(wId, gObj_Money, Amount);
MoneySend(wId, Amount);
free (Packet);
}

但当我尝试构建时，它给了我这样的错误

------ Build started: Project: Post, Configuration: Debug Win32 ------
Compiling...
Post.cpp
.Post.cpp(6) : error C3861: 'gObjIsConnected': identifier not found
.Post.cpp(7) : error C3861: 'DataSend': identifier not found
.Post.cpp(10) : error C2061: syntax error : identifier 'LPCSTR'
.Post.cpp(12) : error C2065: 'IsPost' : undeclared identifier
.Post.cpp(13) : error C3861: 'gObjIsConnected': identifier not found
.Post.cpp(14) : error C2065: 'Command' : undeclared identifier
.Post.cpp(14) : error C3861: 'strcmpi': identifier not found
.Post.cpp(16) : error C2065: 'szPrefix' : undeclared identifier
.Post.cpp(16) : error C3861: 'MessageOutput': identifier not found
.Post.cpp(17) : error C2065: 'szPrefix' : undeclared identifier
.Post.cpp(17) : error C2065: 'PostCost' : undeclared identifier
.Post.cpp(17) : error C2065: 'PostLevel' : undeclared identifier
.Post.cpp(17) : error C3861: 'MessageOutput': identifier not found
.Post.cpp(20) : error C3861: 'gObj_SetInfo': identifier not found
.Post.cpp(21) : error C2065: 'gObj' : undeclared identifier
.Post.cpp(21) : error C2228: left of '.Level' must have class/struct/union
 type is ''unknown-type''
.Post.cpp(21) : error C2065: 'PostLevel' : undeclared identifier
.Post.cpp(23) : error C2065: 'szPrefix' : undeclared identifier
.Post.cpp(23) : error C3861: 'MessageOutput': identifier not found
.Post.cpp(26) : error C2065: 'gObj' : undeclared identifier
.Post.cpp(26) : error C2228: left of '.Money' must have class/struct/union
  type is ''unknown-type''
.Post.cpp(26) : error C2065: 'PostCost' : undeclared identifier
.Post.cpp(28) : error C2065: 'szPrefix' : undeclared identifier
.Post.cpp(28) : error C3861: 'MessageOutput': identifier not found
.Post.cpp(31) : error C2065: 'BYTE' : undeclared identifier
.Post.cpp(31) : error C2065: 'Packet' : undeclared identifier
.Post.cpp(33) : error C2065: 'Packet' : undeclared identifier
.Post.cpp(33) : error C2065: 'BYTE' : undeclared identifier
.Post.cpp(33) : error C2059: syntax error : ')'
.Post.cpp(34) : error C2065: 'Packet' : undeclared identifier
.Post.cpp(34) : error C3861: 'memset': identifier not found
.Post.cpp(35) : error C2065: 'Packet' : undeclared identifier
.Post.cpp(36) : error C2065: 'Packet' : undeclared identifier
.Post.cpp(37) : error C2065: 'Packet' : undeclared identifier
.Post.cpp(37) : error C2065: 'gObj' : undeclared identifier
.Post.cpp(37) : error C2228: left of '.Nick' must have class/struct/union
type is ''unknown-type''
.Post.cpp(37) : error C2065: 'gObj' : undeclared identifier
.Post.cpp(37) : error C2228: left of '.Nick' must have class/struct/union
type is ''unknown-type''
.Post.cpp(37) : error C3861: 'memcpy': identifier not found
.Post.cpp(37) : error C3861: 'strlen': identifier not found
.Post.cpp(38) : error C2882: 'Text' : illegal use of namespace identifier in expression
.Post.cpp(38) : error C3861: 'sprintf': identifier not found
.Post.cpp(39) : error C2065: 'Packet' : undeclared identifier
.Post.cpp(39) : error C3861: 'memcpy': identifier not found
.Post.cpp(39) : error C3861: 'strlen': identifier not found
.Post.cpp(40) : error C3861: 'strlen': identifier not found
.Post.cpp(41) : error C2065: 'Packet' : undeclared identifier
.Post.cpp(42) : error C2065: 'Packet' : undeclared identifier
.Post.cpp(43) : error C2065: 'gObj' : undeclared identifier
.Post.cpp(43) : error C2228: left of '.Money' must have class/struct/union
type is ''unknown-type''
.Post.cpp(43) : error C2065: 'PostCost' : undeclared identifier
.Post.cpp(44) : error C2065: 'gObj_Money' : undeclared identifier
.Post.cpp(44) : error C3861: 'gObj_Write': identifier not found
.Post.cpp(45) : error C3861: 'MoneySend': identifier not found
.Post.cpp(46) : error C2065: 'Packet' : undeclared identifier
.Post.cpp(46) : error C3861: 'free': identifier not found
Build log was saved at "file://c:Documents and SettingsMihaiDesktopFolder nouPostPostDebugBuildLog.htm"
Post - 56 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

我需要做什么？

我该怎么做才能让它发挥作用。

我正在使用：Visual C++ 2008 Express Edition。