dohide = 0;
dosubhide = 0;

function showLayer(layername)
{
	if (document.getElementById(layername)) {
		var menu = document.getElementById(layername);
		var pname = layername.replace(/nav/i, 'ln');
		var parentobj = document.getElementById(pname).parentNode; 
		if (menu) {
			menu.style.top = get_position(parentobj, "Top") + parentobj.offsetHeight;
			menu.style.left = get_position(parentobj, "Left");
			menu.style.position = "absolute";
			menu.style.zIndex = "1000";
			menu.style.width = parseInt(parentobj.offsetWidth) + "px";
			menu.style.display = "";
		}
	}
}

function show_sub(layername, parentname, parentlayer)
{
	if (document.getElementById(layername)) {
		var submenu = document.getElementById(layername);
		var subparentobj = document.getElementById(parentname); 
		var	parobj = document.getElementById(parentlayer);
		if (subparentobj) {
			submenu.style.top = parobj.offsetTop + subparentobj.offsetTop + 10;
			submenu.style.left = parobj.offsetLeft + (subparentobj.offsetLeft + subparentobj.offsetWidth) - 10;
			submenu.style.position = "absolute";
			submenu.style.zIndex = "1000";
			submenu.style.display = "";
		}
	}
}

function hideLayer(layername)
{
	if (document.getElementById(layername)) {
		document.getElementById(layername).style.display = "none";
	}
}

function get_position(obj, type)
{
	var retval = 0;

	if (type == "Left" && obj.x) {
		return obj.x;
	}
	else if (type == "Top" && obj.y) {
		return obj.y;
	}
	else {
		while (obj.offsetParent) {
			if (obj && obj.style && obj.style.position) obj.style.position = "relative";
			retval += eval("obj.offset" + type);
			obj = obj.offsetParent;
		}
		return retval;
	}
}

function hide_layers()
{
	divs = document.getElementsByTagName("div");
	g = 0;
	while (divs[g]) {
		if (divs[g].id.substring(0, 4) == "nav_") {
			hideLayer(divs[g].id);
		}
		g++;
	}
	hide_sub_layers();
}

function hide_sub_layers()
{
	divs = document.getElementsByTagName("div");
	g = 0;
	while (divs[g]) {
		if (divs[g].id.substring(0, 7) == "subnav_") {
			hideLayer(divs[g].id);
		}
		g++;
	}
}

function row_col(obj, colour)
{
	obj.parentNode.parentNode.style.backgroundColor = colour;
}