Need help on simple code

1>------ Build started: Project: This, Configuration: Debug Win32 ------
1>Linking...
1>MSVCRTD.lib(crtexe.obj) : error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup
1>C:\Users\Familia Belem\Documents\Visual Studio 2008\Projects\Project1\This\Debug\This.exe : fatal error LNK1120: 1 unresolved externals
1>Build log was saved at "file://c:\Users\Familia Belem\Documents\Visual Studio 2008\Projects\Project1\This\This\Debug\BuildLog.htm"
1>This - 2 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

#include <windows.h>    


int WINAPI Main(HINSTANCE hInstance,
                HINSTANCE hPrevInstance,
                LPSTR lpCmdLine,
                int nShowCmd)
{
    MessageBox(NULL,
               L"Hack criado no dia 06/01/10",
               L"Felipeb18's hack",
               MB_ICONEXCLAMATION | MB_OK);
    return 0;
}