/* BEGIN NAV MENUS */
var last_subnav = '';
var last_top = '';
var last_left = '';
var mouse_over_item = new Array();
var mouse_over_subitem = new Array();
function subnav_change(ob_a, subnav){
	//hide_subnav();
	if (subnav == '') {
		// mouse out item
		mouse_over_item[last_subnav] = false;
		hide_subnav(last_subnav, false);
	} else {
		// mouse over item
		// kill previous drop-down if there is one
		if (last_subnav && last_subnav != subnav){
			hide_subnav(last_subnav, true);
		}
		// store current subnav for later use
		last_subnav = subnav;
		last_top = (_offsetTop(ob_a) + ob_a.offsetHeight) + 'px';
		last_left = _offsetLeft(ob_a) + 'px';
		// display subnav
		show_subnav()
		// set over states for link and drop-down
		mouse_over_item[subnav] = true;
		mouse_over_subitem[subnav] = false;
	}
}
function mouse_over_subnav(subnav, mouse_over){
	// mouse over / out subnav
	mouse_over_subitem[subnav] = mouse_over;
	if (mouse_over == false){
		hide_subnav(last_subnav, false);
	} else {
		mouse_over_item[subnav] = false;
		show_subnav()
	}
}
function show_subnav(){
	// setup DIV's position and show
	ob_subnav = document.getElementById(last_subnav);
	ob_subnav.style.top = last_top;
	ob_subnav.style.left = last_left;
	ob_subnav.style.display = '';
	// setup IFrame shim hack to make IE overlay select boxes
	ob_iframe = document.getElementById('div_shim');
	ob_iframe.width = ob_subnav.offsetWidth;
	ob_iframe.height = ob_subnav.offsetHeight;
	ob_iframe.style.top = last_top;
	ob_iframe.style.left = last_left;
	ob_iframe.style.display = '';
}
function hide_subnav(subnav, keep_shim){
	//alert(last_subnav + ", " + subnav + ', ' + mouse_over_item[subnav] + ', ' + mouse_over_subitem[subnav]);
	// hide subnav if needed, called from settimeout('', 100) to give slight delay required for correct operation
	if (mouse_over_item[subnav] == false && mouse_over_subitem[subnav] == false) {
		document.getElementById(subnav).style.display = 'none';
		// kill IFrame shim normally except when triggered from new subnav
		if (!keep_shim) {
			ob_iframe = document.getElementById('div_shim').style.display = 'none';
		}
	}
}
/*
IE and Mozilla render the this.offsetLeft and this.offsetTop properties differently, 
so instead use these functions to make them behave the same.  Basically IE reports
offset from the parent object and everything else reports it from the page. These
functions recursively go to the parent objects and add up offsets.
*/
function _offsetLeft(ob) {
	var x = ob.offsetLeft, parent = ob.offsetParent;
	while(parent) {
		x += parent.offsetLeft;
		parent = parent.offsetParent;
	}
	return x;
}
function _offsetTop(ob) {
	var x = ob.offsetTop, parent = ob.offsetParent;
	while(parent) {
		x += parent.offsetTop;
		parent = parent.offsetParent;
	}
	return x;
}
/* END NAV MENUS */