/************** Zoom effect JS ****************/

// init arrays
var scrollers = Array;
scrollers['headerimage'] = { timer: null };
scrollers['featureslide'] = { timer: null };
var curSlide = 1;

// easing
function cubicInOut(t, b, c, d)
{
	if ((t/=d/2) < 1) return c/2*t*t*t + b;
	return c/2*((t-=2)*t*t + 2) + b;
}

// easing
function sineInOut(t, b, c, d)
{
	return -c/2 * (Math.cos(Math.PI*t/d) - 1) + b;
}
		
// perform the move	
function move(scroll,container)
{
	if (scroll.time > scroll.duration)
	{
		clearInterval(scrollers[container].timer);
		scrollers[container].timer = null;
	}
	else
	{	
		element = document.getElementById(scroll.container);
		element.scrollLeft = cubicInOut(scroll.time, scroll.begin, scroll.change, scroll.duration);
		scroll.time++;
	}
}

// initialise the move
function startMove(container,pos,duration)
{	
	if (scrollers[container].timer != null)
	{
		clearInterval(scrollers[container].timer);
		scrollers[container].timer = null;
	}
	
	start = document.getElementById(container).scrollLeft;
	end = pos;
	begin = document.getElementById(container).scrollLeft;	
										
	scrollers[container].time = 0;
	scrollers[container].begin = begin;
	scrollers[container].change = end - start;
	scrollers[container].duration = duration;
	scrollers[container].container = container;
	scrollers[container].timer = setInterval(function(){move(scrollers[container],container);}, 15);
}


function getImgPath(e,state)
{
	if(!(imgSRC = getPattern(document.getElementById(e).childNodes[0].currentStyle.backgroundImage,"\"(.*)_(.*)\.png\"")))
	 imgSRC = getPattern(document.getElementById(e).childNodes[0].currentStyle.filter,"src='(.*)_(.*)\.png',");
	if (state)
		return imgSRC+"_on.png";
	else
		return imgSRC+"_off.png";
	//return imgSRC+".png";
}





// set active tabs
function setNavClass(navID)
{
	if(/MSIE (5\.5|6\.)/.test(navigator.userAgent))
	{
		fixElement('hn_live1',getImgPath('hn_live1',false));
		fixElement('hn_band2',getImgPath('hn_band2',false));
		fixElement('hn_album3',getImgPath('hn_album3',false));
		fixElement(navID,getImgPath(navID,true));	
	}
	else
	{
		document.getElementById('hn_live1').className = 'off';
		document.getElementById('hn_band2').className = 'off';
		document.getElementById('hn_album3').className = 'off';	
		document.getElementById(navID).className = 'on';	
	}
}

// change the navigation (perform all functions)
function changeNav(nav)
{
	if (nav == 'left')
	{
		nav = curSlide;
		if (nav > 1)
		{
			nav--;
			curSlide = nav;
		}
	}
	if (nav == 'right')
	{
		nav = curSlide;
		if (nav < 3)
		{
			nav++;	
			curSlide = nav;
		}
	}	
	if (nav == 1)
	{
		document.getElementById('home_arrow_left').style.display = "none";
		document.getElementById('home_arrow_right').style.display = "block";
		if (document.getElementById('headerimage') != null)
		{
			startMove('headerimage',0,80);
			setNavClass('hn_live1');	
		} 
		startMove('featureslide',0,100); 			
		return false;
	}
	if (nav == 2)
	{
		document.getElementById('home_arrow_left').style.display = "block";
		document.getElementById('home_arrow_right').style.display = "block";
		
		if (document.getElementById('headerimage') != null)
		{	
			startMove('headerimage',998,80);
			setNavClass('hn_band2');			
		}
		startMove('featureslide',998,100); 					
		return false;
	}
	if (nav == 3)
	{
		document.getElementById('home_arrow_left').style.display = "block";
		document.getElementById('home_arrow_right').style.display = "none";
		
		if (document.getElementById('headerimage') != null)
		{	
			startMove('headerimage',1996,80);
			setNavClass('hn_album3');	
		}
		startMove('featureslide',1996,100);			
		return false;
	}	
}


function fixElement(e,imgSrc)
{
	element = document.getElementById(e).childNodes[0];
	if (imgSrc)
	{
    	element.style.backgroundImage = "none";
		element.style.backgroundColor = "transparent";
		element.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" +
		imgSrc + "',sizingMethod='crop')";
	}
}

function getPattern(inputString,regPat)
{
//alert("PAT: "+regPat);
//alert("INP: "+inputString);
	var reg=new RegExp(regPat,"i");
	var ar = reg.exec(inputString);
 	if(ar!=null){
 	// alert("MATCH: "+ar[1]);
 	 return ar[1];
 	}
	return null;
}