var tetaSSN;
var tetaHSN;
var fadeIntSN  = null;
var showIntSN  = null;
var fadeElemSN = null;
var showElemSN = null;
var fadeUpToSN = null;
var doHideSN;
var isIE     = null;
var currPageOnSN = null;


function checkIE(){
	if(document.all) isIE = true;
	else isIE = false;
}

checkIE();

function setOpacity(elem, value){
	if(isIE){
		elem.style.filter  = "alpha(opacity="+(Math.ceil(value*100))+")";
	} else {
		elem.style.opacity = value;
	}
}

function getOpacity(elem){
	if(isIE){
		retVal = parseFloat(elem.style.filter.replace("alpha(opacity=", "").replace(")", ""))/100;
	} else {
		retVal = elem.style.opacity;
	}
	return retVal;
}


function fadeSN(){
	opacity = getOpacity(fadeElemSN);
	if (opacity <= fadeUpToSN){
		clearInterval(fadeIntSN);
		fadeIntSN = null;
		if(doHideSN) fadeElemSN.style.display = "none";
		if(fadeCallBack) {
			fadeCallBack();
		}
	}
	
	setOpacity(fadeElemSN, Math.sin(tetaHSN));
	tetaHSN += 5*(Math.PI/180);
	
}

var fadeCallBack = null;
function startFadeSN(elem, upto, hide, callBack){
	if(callBack){
		fadeCallBack = callBack;
	}
	if(fadeIntSN == null){
		fadeElemSN   = elem;
		fadeUpToSN   = upto;
		doHideSN     = hide;
		
		setOpacity(elem, 1);
		
		tetaHSN      = Math.PI/2;
		fadeIntSN = setInterval("fadeSN()", 50);
	}
}	

function showSN(){
	opacity = getOpacity(showElemSN);
	if (opacity >= 1){
		clearInterval(showIntSN);
		showIntSN = null;
	}
	setOpacity(showElemSN, Math.sin(tetaSSN));
	tetaSSN +=  5*(Math.PI/180);
	
}


function startShowSN(elem){
	if(showIntSN == null){
		showElemSN   = elem;
		setOpacity(elem, 0)
		elem.style.display = "";
		tetaSSN       = 0;
		showIntSN = setInterval("show()", 100);
	}
	var currPageOnSN = elem;

}