//Retrieve a particular first-level menu header.
function primenav(name) {
	return document.getElementById("prime-nav-"+name);
}
//Retrieve a particular second-level menu.
function secnav(name) {
	return document.getElementById("sec-nav-"+name);
}
//Set all primary and secondary menus to their hidden states.
function reset() {
	primenav('bookshelf').className='';
	primenav('lauren').className='';
	primenav('readers').className='';
	primenav('sellers').className='';
	primenav('contact').className='';

	secnav('blank').style.display='none';
	secnav('bookshelf').style.display='none';
	secnav('lauren').style.display='none';
	secnav('readers').style.display='none';
	secnav('sellers').style.display='none';
	secnav('contact').style.display='none';
}
//Set the indicated primary and secondary menus to their active states.
function select(name) {
	secnav(name).style.display='block';
	if(name != 'blank') {
		primenav(name).className='selected';
	}
}
//Switch second-level menus.
function sw(name) {
	reset();
	select(name);
}

function init_menus() {
    var pnav=document.getElementById('prime-nav');
	menuitems=pnav.getElementsByTagName('li');
	
	for(var i=0; i < menuitems.length; i++) {
	    menuitems[i].submenu=menuitems[i].id.substr(10);
	    menuitems[i].onmouseover=function () { sw(this.submenu); };
	}
	
	sw('blank');
}