作ったプログラムでTAB STOPが有効にならない

int APIENTRY WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,int       nCmdShow )
{
    MSG msg;
    if( !InitInstance( hInstance, nCmdShow ) )return 0;
    while( GetMessage(&msg, NULL, 0, 0) )
    {
            TranslateMessage( &msg );
            DispatchMessage( &msg );
    }
    return msg.wParam;
}

int APIENTRY WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,int       nCmdShow )
{
    MSG msg;
    if( !InitInstance( hInstance, nCmdShow ) )return 0;
    while( GetMessage(&msg, NULL, 0, 0) )
    {
    　　if ( !::IsDialogMessage(hWnd,&msg) ){
            TranslateMessage( &msg );
            DispatchMessage( &msg );
        }
    }
    return msg.wParam;
}