To Assign an Image to an Article
First, upload your image using the Image Tab. Once the image is uploaded and a thumbnail is created, you can attach that image to an article.
Go to the Articles Tab and select the article to which you want to append it. Click on Insert Image on the left navigation. Scroll through the images until you find the image you want. Click Append or Replace as appropriate. Close the image browser instance. Click Save on your article. YOU MUST SAVE the article after inserting the image.