how to add javascript animations to change background code example

Example 1: javascript change frame background

window.frames['frameName'].document.body.style.backgroundColor = "#000";

Example 2: how to add a background image in html

<!-- HTML -->
<div id="imageDiv"></div>

<!-- CSS -->
<style>
  #imageDiv {
	background-image: url('someimage.png');
  }
</style>