You are free to write article on any topic. But, ensure that the article should be original and not be a copied content. Also, read the posting guidelines and help topics to present your contents in better way.
Read full answer to your question in similar forum question by you. It appears that being a new member you have posted the thread twice. Do not worry. You keep on following both the threads with similar topic till one thread is closed by the forum editors. Welcome to ISC once again. Check for answer in the duplicate thread and you may respond there so as to confirm as to which forum thread you are following. It will make the things easier for you.