gistfile1.c

  switch (message)
	{
	case WM_CREATE:
		hChannelMembers = CreateWindow(_T("LISTBOX"), _T(""),
			WS_CHILD | WS_VISIBLE | LBS_STANDARD, 
			0, 0, 0,0, hWnd, IDC_MEMBERS, hInst, NULL);

		hMessages = CreateWindow(_T("LISTBOX"), _T(""),
			WS_CHILD | WS_VISIBLE | LBS_STANDARD, 
			0, 0, 0,0, hWnd, IDC_MESSAGES, hInst, NULL);

		hInputBox = CreateWindow(_T("EDIT"), _T(""),
			WS_CHILD | WS_VISIBLE | WS_BORDER, 
			0, 0, 0,0, hWnd, NULL, hInst, NULL);

		hSendButton = CreateWindow(_T("BUTTON"), _T("&Send"),
			WS_CHILD | WS_VISIBLE | BS_DEFPUSHBUTTON, 
			0, 0, 0,0, hWnd, IDC_SEND, hInst, NULL);

		break;
	case WM_SIZE:
		{
			int nWidth = LOWORD(lParam); 
			int nHeight = HIWORD(lParam);
			const int nMembersWidth = 200;
			const int nEditBoxHeight = 23; // http://msdn.microsoft.com/en-us/library/aa511279.aspx#sizingspacing
			const int buttonWidth = 40;

			SetWindowPos(hChannelMembers, NULL, 0, 0, nMembersWidth, nHeight, SWP_NOZORDER);
			SetWindowPos(hMessages, NULL, nMembersWidth, 0, nWidth-nMembersWidth, nHeight-nEditBoxHeight, SWP_NOZORDER);
			SetWindowPos(hInputBox, NULL, nMembersWidth, nHeight-nEditBoxHeight, nWidth-nMembersWidth - buttonWidth, nHeight, SWP_NOZORDER);
			SetWindowPos(hSendButton, NULL, 
				nWidth - buttonWidth, 
				nHeight-nEditBoxHeight, 
				buttonWidth, 
				nHeight, SWP_NOZORDER);
		}