You can edit... But that option is not working good here.. All your changes will be gone and images also will be removed.. Better you don't use it. Instead of that you can submit the same article again and admin will take care of it.
Bhardwaj, I had experience that if the article is edited I could not find the headings for which I had used html tags while submitting the article. For that I have asked this question as forum thread.
