Hello, Is WriteExcel backwards compactible? meaning can the new version operate old code that was meant for a really old WriteExcel version? Just when I tried using something like add_format, it complained add_format wasnt there (instead there is addformat), and the person already using WriteExcel installed it ages ago. Is it safe to use the same old code if I updated WriteExcel? If there is any flaws in doing so please let me know, no matter how small they are. Thanks.