Add the following statements to the InitInstance function to establish the client-area rectangles in which different messages are displayed:
hDC = GetDC(hWnd);
GetTextMetrics(hDC, &textmetric);
ReleaseDC(hWnd, hDC);
nLineHeight = textmetric.tmExternalLeading + textmetric.tmHeight;
rect.left = GetDeviceCaps(hDC, LOGPIXELSX) / 4; /* 1/4 inch */
rect.right = GetDeviceCaps(hDC, HORZRES);
rect.top = GetDeviceCaps(hDC, LOGPIXELSY) / 4; /* 1/4 inch */
rect.bottom = rect.top + nLineHeight;
rectMouse = rect;
rect.top += nLineHeight;
rect.bottom += nLineHeight;
rectButton = rect;
rect.top += nLineHeight;
rect.bottom += nLineHeight;
rectKeyboard = rect;
rect.top += nLineHeight;
rect.bottom += nLineHeight;
rectCharacter = rect;
rect.top += nLineHeight;
rect.bottom += nLineHeight;
rectScroll = rect;
rect.top += nLineHeight;
rect.bottom += nLineHeight;
rectTimer = rect;