wndclass.style = CS_HREDRAW | CS_VREDRAW;
wndclass.lpfnWndProc = MainWndProc;
wndclass.cbClsExtra = 0;
wndclass.cbWndExtra = 0;
wndclass.hInstance = hInstance;
wndclass.hIcon = LoadIcon(NULL, IDI_WINLOGO);
wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
wndclass.hbrBackground = (HBRUSH)COLOR_WINDOW;
wndclass.lpszMenuName = NULL;
wndclass.lpszClassName = lpszAppName
to jest moja klasa okna ale ja wiem gdzie to wpisać tylko nie wiem jak??