Add the WM_LBUTTONUP and WM_LBUTTONDOWN Cases

Add the WM_LBUTTONUP and WM_LBUTTONDOWN cases to process
mouse-button input messages. Add the following statements to the window
function:

case WM_LBUTTONDOWN:

wsprintf(ButtonText, “WM_LBUTTONDOWN: %x, %d, %d”,

wParam, LOWORD(lParam), HIWORD(lParam));

InvalidateRect(hWnd, &rectButton, TRUE);

break;

case WM_LBUTTONUP:

wsprintf(ButtonText, “WM_LBUTTONUP: %x, %d, %d”,

wParam, LOWORD(lParam), HIWORD(lParam));

InvalidateRect(hWnd, &rectButton, TRUE);

break;