/**
 * @author mmurray
 */
var selected = false;
function showAct(){
	if(selected){
		document.getElementById("nav_"+selected).className ="";
		document.getElementById("subnav_"+selected).style.display = "none";
	}
	selected = "activities";
	myBut = document.getElementById("nav_"+selected);
	myBut.className = "cur";
	myEle = document.getElementById("subnav_"+selected);
	myEle.style.display = "block";
	var butPos = findPos(document.getElementById("nav_"+selected));
	var bodPos = findPos(document.getElementById("body"));
	myEle.style.paddingLeft = (butPos[0] - bodPos[0]) + "px";
}
function showHome(){
	if(selected){
		document.getElementById("nav_"+selected).className ="";
		document.getElementById("subnav_"+selected).style.display = "none";
	}
	selected = "home";
	myBut = document.getElementById("nav_"+selected);
	myBut.className = "cur";
	myEle = document.getElementById("subnav_"+selected);
	myEle.style.display = "block";
	var butPos = findPos(document.getElementById("nav_"+selected));
	var bodPos = findPos(document.getElementById("body"));
	myEle.style.marginLeft = (butPos[0] - bodPos[0]) + "px";
}
function showAbout(){
	if(selected){
		document.getElementById("nav_"+selected).className ="";
		document.getElementById("subnav_"+selected).style.display = "none";
	}
	selected = "about";
	myBut = document.getElementById("nav_"+selected);
	myBut.className = "cur";
	myEle = document.getElementById("subnav_"+selected);
	myEle.style.display = "block";
	var butPos = findPos(document.getElementById("nav_"+selected));
	var bodPos = findPos(document.getElementById("body"));
	myEle.style.paddingLeft = (butPos[0] - bodPos[0]) + "px";
}
function showLinks(){
	if(selected){
		document.getElementById("nav_"+selected).className ="";
		document.getElementById("subnav_"+selected).style.display = "none";
	}
	selected = "links";
	myBut = document.getElementById("nav_"+selected);
	myBut.className = "cur";
	myEle = document.getElementById("subnav_"+selected);
	myEle.style.display = "block";
	var butPos = findPos(document.getElementById("nav_"+selected));
	var bodPos = findPos(document.getElementById("body"));
	myEle.style.paddingLeft = (butPos[0] - bodPos[0]) + "px";
}
function showStrategy(){
	if(selected){
		document.getElementById("nav_"+selected).className ="";
		document.getElementById("subnav_"+selected).style.display = "none";
	}
	selected = "strategy";
	myBut = document.getElementById("nav_"+selected);
	myBut.className = "cur";
	myEle = document.getElementById("subnav_"+selected);
	myEle.style.display = "block";
	var butPos = findPos(document.getElementById("nav_"+selected));
	var bodPos = findPos(document.getElementById("body"));
	myEle.style.paddingLeft = (butPos[0] - bodPos[0]) + "px";
}
function init(){
	var subnav = document.getElementById("subnav");
	var home = document.getElementById("nav_home");
	var act = document.getElementById("nav_activities");
	var strategy = document.getElementById("nav_strategy");
	var links = document.getElementById("nav_links");
	var about = document.getElementById("nav_about");
	var top = document.getElementsByTagName("h1");
	addEvent(home,"click",showHome);
	addEvent(act,"click",showAct);
	addEvent(links,"click",showLinks);
	addEvent(about,"click",showAbout);
	addEvent(strategy,"click",showStrategy);
	var i = Math.round(16*Math.random()) + 1;
	var img = "url(../images/top"+i+".jpg)";
	top[0].style.background = img;
}

function addEvent(obj, evType, fn){ 
 if (obj.addEventListener){ 
   obj.addEventListener(evType, fn, false); 
   return true; 
 } else if (obj.attachEvent){ 
   var r = obj.attachEvent("on"+evType, fn); 
   return r; 
 } else { 
   return false; 
 } 
}

function findPos(obj) {
	var curleft = 0, curtop = 0;
	if (obj.offsetParent) {
		curleft = obj.offsetLeft
		curtop = obj.offsetTop
		while (obj = obj.offsetParent) {
			curleft += obj.offsetLeft
			curtop += obj.offsetTop
		}
	}
	return [curleft,curtop];
}