/*
 * javascript for website navigation control with page header
 * pipi
 */
function doClick(nav) {
	var id_nav;
	var id_sub;
	var havesub=false;
	for (var i = 1; i <= 6; i++) {
		id_nav = "nav" + i;
		id_sub = "sub" + i;
		if(document.getElementById(id_nav)==null){
			continue; 
		}
		if (id_nav != nav.id) {
			document.getElementById(id_nav).className = "nav_link";
			if(null!=document.getElementById(id_sub)){
				document.getElementById(id_sub).style.display = "none";
			}
		}
		else {
			document.getElementById(id_nav).className = "nav_current";
			if(null!=document.getElementById(id_sub)){
				havesub=true;
				document.getElementById(id_sub).style.display = "block";
			}
		}
	}
	if(havesub){
		document.getElementById("subnav").style.display = "block";
	}else{
		document.getElementById("subnav").style.display = "none";
	}
}