function swapContent(targetId,content){
	var target = document.getElementById(targetId);
	target.innerHTML = content;
}

function showDiv(targetId,divId){
	var target = document.getElementById(targetId);
	var div = document.getElementById(divId);
	if(div) target.innerHTML = div.innerHTML;
	
}

function swapThisImg(obj){
	// assuming swapped img is same name with "_on" added
	var path = obj.src.substring(0,obj.src.length-4);
	var ext = obj.src.substring(obj.src.length-4,obj.src.length);
	obj.src = path+'_on'+ext;
}

function swapOutThisImg(obj){
	// assuming swapped img is same name without "_on" at end
	var path = obj.src.substring(0,obj.src.length-7);
	var ext = obj.src.substring(obj.src.length-4,obj.src.length);
	obj.src = path+ext;
}

function swapNav(id,imgId){
	var i = document.getElementById(id);
	i.src = document.getElementById(imgId).src;
}

function swapNavOut(id,imgId){
	var i = document.getElementById(id);
	i.src = document.getElementById(imgId).src;
}