var index = 0;
var dir = 0;

function change()
{
	var nodes = document.getElementById("hbSimpleNav").childNodes;
	var lis=new Array();
	
	for (i=0;i<nodes.length;i++)
		if (nodes[i].nodeType == 1) 
			lis.push(nodes[i]);

	if (dir == 0)
		index++;
	else
		index--;
	
	if (index < 0) {
		dir = 0;
		index = 1;
	} else if (index >= lis.length) {
		dir = 1;
		index = lis.length-2;
	}
		
	lis[index].firstChild.click();
}