[monolithed]

<script type="text/javascript">
window.onload = function(){
	document.getElementById("element").onchange = function(){
		document.getElementById("div").style.background = this.checked ? 'red' : 'black';
	};
};
</script>

<input type="checkbox" id="element" value="#" />
<div id="div" style="width: 100px; height: 20px; background: black"></div>