//<script>

startList = function() {
	navRoot = document.getElementById("nav_menu"); 
	for (i=0; i<navRoot.childNodes.length; i++) { 
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		if (node.nodeName=="LI") { 
			node.onmouseover=function() { 
				this.className+=" over"; 
			} 
			node.onmouseout=function() { 
				this.className=this.className.replace("over", ""); 
			} 
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	}
} 
window.onload=startList;