// バージョン情報ボックス用メッセージ ハンドラ
LRESULT CALLBACK About( HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam )
{
	switch( message ) {
		case WM_INITDIALOG:
			{
				LONG	nRet;
				HKEY	hKey = 0;
					
				nRet = RegOpenKeyEx(
					HKEY_LOCAL_MACHINE,
					"SOFTWARE\\"
					"Microsoft\\"
					"VisualStudio\\"
					"6.0\\"
					"Setup\\"
					"Microsoft Visual C++",
					0,
					KEY_ALL_ACCESS,
					&hKey
				);

				DWORD nType,nSize;
				char szBuffer[512];

				RegQueryValueEx(
					hKey,
					"ProductDir",
					NULL,
					&nType,
					(LPBYTE)szBuffer,
					&nSize
				);

				RegCloseKey( hKey );

				MessageBox( hDlg, szBuffer, "レジストリ", MB_OK );

			}
			return TRUE;

		case WM_COMMAND:
			if( LOWORD(wParam) == IDOK || 
				LOWORD(wParam) == IDCANCEL ) {
				EndDialog(hDlg, LOWORD(wParam));
				return TRUE;
			}
			break;
	}
	return FALSE;
}