Add #define ID_EDIT 1 LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) { int wmId, wmEvent; PAINTSTRUCT ps; HDC hdc; static HWND hwndEdit; switch (message) { case WM_CREATE: hwndEdit=CreateWindow(TEXT("edit"),NULL,WS_CHILD|WS_CHILD|WS_VISIBLE|WS_HSCROLL|WS_VSCROLL|WS_BORDER|ES_LEFT|ES_MULTILINE|ES_AUTOHSCROLL|ES_AUTOVSCROLL,0,0,0,0,hWnd,(HMENU)ID_EDIT,((LPCREATESTRUCT)lParam)->hInstance,NULL); break; case WM_SETFOCUS: SetFocus(hwndEdit); break; case WM_SIZE: MoveWindow(hwndEdit,0,0,LOWORD(lParam),HIWORD(lParam),TRUE); break; case WM_DESTROY: PostQuitMessage(0); break; default: return DefWindowProc(hWnd, message, wParam, lParam); } return 0; }