// preload images
var img_base_url = spn_base_url + "/images/navigation";

var home_img = new Image(); home_img.src = img_base_url + "/home_on.jpg";
var cables_img = new Image(); cables_img.src = img_base_url + "/cables_on.jpg";
var ac_conditioning_img = new Image(); ac_conditioning_img.src = img_base_url + "/ac_conditioning_on.jpg";
var reviews_img = new Image(); reviews_img.src = img_base_url + "/reviews_on.jpg";
var tesla_img = new Image(); tesla_img.src = img_base_url + "/tesla_on.jpg";
var acoustic_img = new Image(); acoustic_img.src = img_base_url + "/acoustic_on.jpg";
var home_theater_img = new Image(); home_theater_img.src = img_base_url + "/home_theater_on.jpg";

function nav_hover (img)
{
	var url = document.URL;
	var i = url.lastIndexOf("/");
	var page_name = url.substr(i+1,url.length-i);
	
	if (page_name == img.id)
		return;
		
	if (page_name == "" && img.id == "home")
		return;
		
	if (active_navigation_button != "" && img.src.indexOf(active_navigation_button) != -1)
		return;
	
	if (img.src.indexOf("_on.jpg") != -1)
	{
		// turn it off
		img.src = img.src.replace("_on.jpg",".jpg");
	}
	else
	{
		// turn it on
		img.src = img.src.replace(".jpg","_on.jpg");
	}
}