Error i BCC5.5

Få felet:

Error: Unresolved external '_main' referenced from C:\PROGRAM\BORLAND\BCC55\LIB\COX32.obj

Vad beror det på?

#define WIN32_LEAN_AND_MEAN
#include <windows.h>

LRESULT CALLBACK WindowProc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
{
	HDC 		hdc;
	PAINTSTRUCT	ps;

	switch(msg)
	{
		case WM_CREATE:
		{
			return(0);
		} break;

		case WM_PAINT:
		{
			hdc = BeginPaint(hwnd, &ps);
			EndPaint(hwnd,&ps);

			return(0);
		} break;

		case WM_DESTROY:
		{
			PostQuitMessage(0);
			return(0);
		} break;

		default: break;
	}

	return(DefWindowProc(hwnd, msg, wparam, lparam));
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
	WNDCLASS winclass;
	HWND	 hwnd;
	MSG	 msg;

	winclass.style		= CS_DBLCLKS | CS_OWNDC |
				  CS_HREDRAW | CS_VREDRAW;
	winclass.lpfnWndProc	= WindowProc;
	winclass.cbClsExtra	= 0;
	winclass.cbWndExtra	= 0;
	winclass.hInstance	= hInstance;
	winclass.hIcon		= LoadIcon(NULL, IDI_APPLICATION);
	winclass.hCursor	= LoadCursor(NULL, IDC_ARROW);
	winclass.hbrBackground	= (HBRUSH)GetStockObject(BLACK_BRUSH);
	winclass.lpszMenuName	= NULL;
	winclass.lpszClassName	= "DirectXWindowClass";

	if (!RegisterClass(&winclass))
		return(0);

	if (!(hwnd = CreateWindow("DirectXWindowClass",
				"DirectX fönster",
				WS_POPUP | WS_VISIBLE,
				0,0,
				640,
				480,
				NULL,
				NULL,
				hInstance,
				NULL)))

	while(1)
	{
		if(PeekMessage(&msg,NULL,0,0,PM_REMOVE))
		{
			if(msg.message == WM_QUIT)
				break;

			TranslateMessage(&msg);
			DispatchMessage(&msg);
		}
	}

	return(msg.wParam);
}