C++ GUI this tutorial i found isnt working.

[flamewavetech]

i found a tutorial and it gave me this code

#include <windows.h>
#include <tchar.h>
#include "resource.h"
 
BOOL MainDialogProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    return FALSE;
}
 
int _tmain(void)
{
    DialogBoxParam(GetModuleHandle(NULL), MAKEINTRESOURCE(IDD_DIALOG1), 
        NULL, (DLGPROC)MainDialogProc, 0);
    return 0;
}

im using VC++ compiler so i went to insert and made a new dialog and saved it. i then compiled it and got the following errors:

--------------------Configuration: test GUI4 - Win32 Debug--------------------
Compiling...
source.cpp
Linking...
LIBCD.lib(wincrt0.obj) : error LNK2001: unresolved external symbol _WinMain@16
Debug/test GUI4.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.

test GUI4.exe - 2 error(s), 0 warning(s)


So can someone please tell me why it isnt working?