/*
 * Define navigation visibility
 * @param subnavi, element ID
 * @param display, element display style
 * @param p, whether to enter recursion (no matter what, recursion done only once)
*/
var previous = '';

function naviVisibility(subnavi, dis, p) {
	// If showing a new navigation element, hide the previous one
	if(p) {
		if(previous != '') 
			naviVisibility(previous, 'none', false);
			
		previous = subnavi; 
	}
	
	if (document.getElementById) {
		document.getElementById(subnavi).style.display = dis;
	}
	else {
		if (document.layers) { 
			document.subnavi.display = dis;
		}
		else {
			document.all.subnavi.style.display = dis;
		}
	}
}