/*****************************************/
/** Javascript for animation
/*****************************************/

var opac = 100;
var maxbgopac = 0.5;
var maxcontentopac = 1;
var maxmsgopac = 0.8;
var rate = 20;
var bgspeed=10;

var showmsg = false;

var topoffset = 0;

function toggleBgFade()
{
	if (bgFadeShowing())
		hideBgFade();
	else
		showBgFade();
}

function showBgFade()
{
	fadeIn();
}

function hideBgFade()
{
	fadeOut();
}

function showBgMsg()
{
	showmsg = true;
	if (extlink = document.getElementById('ext-link')){
		if (bgcontent_div = document.getElementById('bgcontent')){
			extlink.href = bgcontent_div.src;
		}
	}
	showBgFade();
}

function hideBgMsg()
{
	showmsg = false;
	bgmsg_div = document.getElementById('bgmsg');
	bgmsg_div.style.display = 'none';
}

function showHome()
{
	showmsg = false;
	if (bgcontent_div = document.getElementById('bgcontent')){
		bgcontent_div.src = "index.php";
	}
	showBgFade();
}

function fadeIn()
{
	if (opac >= 100)
		return;
		
	bgfade_div = document.getElementById('bgfade');
	bgcontent_div = document.getElementById('bgcontent');
	bgmsg_div = document.getElementById('bgmsg');
	
	if (bgfade_div && bgcontent_div){
		if (bgfade_div.style.display != 'block'){
			changeOpac(0, 'bgfade');
			bgfade_div.style.display = 'block';
		}
		if (bgcontent_div.style.display != 'block'){
			changeOpac(0, 'bgcontent');
			bgcontent_div.style.display = 'block';
		}
		if (showmsg && bgmsg_div.style.display != 'block'){
			changeOpac(0, 'bgmsg');
			bgmsg_div.style.display = 'block';
		}

		if (opac < 100){
			opac = (opac+rate <= 100) ? opac+rate:100;
			changeOpac(opac*maxbgopac, 'bgfade');
			changeOpac(opac*maxcontentopac, 'bgcontent');
			changeOpac(opac*maxmsgopac, 'bgmsg');
			setTimeout('fadeIn()', 0);
		}
	} 
}

function fadeOut()
{
	bgfade_div = document.getElementById('bgfade');
	bgcontent_div = document.getElementById('bgcontent');
	bgmsg_div = document.getElementById('bgmsg');
	if (bgfade_div && bgcontent_div){
		if (opac > 0){
			opac = (opac-rate > 0) ? opac-rate:0;
			changeOpac(opac*maxbgopac, 'bgfade');
			changeOpac(opac*maxcontentopac, 'bgcontent');
			changeOpac(opac*maxmsgopac, 'bgmsg');
			setTimeout('fadeOut()', 0);
		} else {
			bgfade_div.style.display = 'none';
			bgcontent_div.style.display = 'none';
			bgmsg_div.style.display = 'none';
		}
		
	}
}

function bgFadeShowing()
{
	bgfade_div = document.getElementById('bgfade');
	return (bgfade_div.style.display != 'none');
}


//change the opacity for different browsers
function changeOpac(opacity, id) {
    var object = document.getElementById(id).style;
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
}