Add a WM_LBUTTONDBLCLK case to process mouse-button input messages. Add the following statements to the window function:
case WM_LBUTTONDBLCLK:
wsprintf(ButtonText, “WM_LBUTTONDBLCLK: %x, %d, %d”,
wParam, LOWORD(lParam), HIWORD(lParam));
InvalidateRect(hWnd, &rectButton, TRUE);
break;