Adding a random background image to your Joomla! template
In distinguishing your Joomla! template from others, there are a number of extensions for Joomla! to help you, including one that allows you to display a random image as your template's background image for the<body> element.
Getting ready
You need to install the extension called Random Background. You can find the file's download link on the Joomla! website at http://extensions.joomla.org/extensions/style-a-design/templating/6054. Once you have saved the extension files somewhere on your computer, log in to your website's Joomla! administration panel (if Joomla! is installed at example.com, the administration panel is typically accessible at example.com/administrator), and select the Install/Uninstall option from the Extensions option in the primary navigation:
You will then be presented with a form, from where you can upload the extension's .zip file. Select the file from your computer, and then click on the Upload File ...
