#include <windows.h>

LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);
HINSTANCE g_hInst;
LPSTR lpszClass="First";

int APIENTRY WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance
          ,LPSTR lpszCmdParam,int nCmdShow)
{
    HWND hWnd;
    MSG Message;
    WNDCLASS WndClass;
    g_hInst=hInstance;

    WndClass.cbClsExtra=0;
    WndClass.cbWndExtra=0;
    WndClass.hbrBackground=(HBRUSH)GetStockObject(WHITE_BRUSH);
    WndClass.hCursor=LoadCursor(NULL,IDC_ARROW);
    WndClass.hIcon=LoadIcon(NULL,IDI_APPLICATION);
    WndClass.hInstance=hInstance;
    WndClass.lpfnWndProc=(WNDPROC)WndProc;
    WndClass.lpszClassName=lpszClass;
    WndClass.lpszMenuName=NULL;
    WndClass.style=CS_HREDRAW | CS_VREDRAW;
    RegisterClass(&WndClass);

    hWnd=CreateWindow(lpszClass,lpszClass,WS_OVERLAPPEDWINDOW,
          CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,
          NULL,(HMENU)NULL,hInstance,NULL);
    ShowWindow(hWnd,nCmdShow);

    while(GetMessage(&Message,0,0,0)) {
        TranslateMessage(&Message);
        DispatchMessage(&Message);
    }
    return Message.wParam;
}

LRESULT CALLBACK WndProc(HWND hWnd,UINT iMessage,WPARAM wParam,LPARAM lParam)
{
    switch(iMessage) {
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }
    return(DefWindowProc(hWnd,iMessage,wParam,lParam));
}

=================================================================================아래 에러요?
[BCC32 Warning] sdiapp.cpp(37): W8057 Parameter 'hPrevInstance' is never used
[BCC32 Warning] sdiapp.cpp(37): W8057 Parameter 'lpszCmdParam' is never used
[ILINK32 Error] Error: Unresolved external '__InitVCL' referenced from D:\PROGRAM FILES\CODEGEAR\RAD STUDIO\6.0\LIB\CP32MT.LIB|crtlvcl
[ILINK32 Error] Error: Unresolved external '__ExitVCL' referenced from D:\PROGRAM FILES\CODEGEAR\RAD STUDIO\6.0\LIB\CP32MT.LIB|crtlvcl