What if you need to dynamically change the Body Background-image based on whether the Page IsPostback? You have a CSS Stylesheet for the page, and that Stylesheet has a background-image defined for the body tag. So what is the [workaround]? You first must define the body tag on the page as a server control. Then you can access the body control via code in your page: 1: protected void Page_Load(object sender, EventArgs e) 2: { 3: if (!IsPostBack) 4: { 5: var rnd = new Random(); 6: // the background ......