写dll链接时出错?

[wwzh]

//mydll.h
extern "C"_declspec(dllexport) int Add(int x,int y);
//mydll.cpp
#include "mydll.h"
extern "C"_declspec(dllexport) int Add(int x,int y)
{
return(x+y);
}
出现如下错误:
Linking...
Creating library Debug/mydll.lib and object Debug/mydll.exp
libcd.lib(crt0.obj) : error LNK2001: unresolved external symbol _main
Debug/mydll.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.
怎么改?

[wwwsq]

工程项目设置不对，VC链接exe文件去了

[wwzh]

可是我用mfc写的时候没有错误.