var mainContent = null;
var sliderStyle = null;
var fps = 30;
var isOpera = (window.opera) ? true : false;
var d = isOpera ? 600 : 1000;
var f = d/1000 * fps;
var balken_calc_top_old = getScrollTop();
var balken_old_top = getScrollTop();
var naviHeight = null;
var naviMarginTop = 15;
var contentHeight = null;
var headerHeight = 135;

function getScrollTop(){
	var _1 = 0;
	if(typeof(window.pageYOffset) == "number") {
		_1 = window.pageYOffset;
	} else {
		if(document.body && document.body.scrollTop) {
			_1 = document.body.scrollTop;
		} else {
			if(document.documentElement && document.documentElement.scrollTop) {
				_1 = document.documentElement.scrollTop;
			}
		}
	}
	return _1;
}

function updateSlider(){
		var _2 = getScrollTop();
		if(_2 != balken_old_top) {
			var _3 = -(_2 - balken_old_top) * (3/f) * ((3/f) - 2) + balken_old_top;
			if(Math.abs(_3 - _2) < 3){
				_3 = _2;
			} else {
				_3 = Math.round(_3);
			}
			balken_old_top = _3;
			if(headerHeight < _3) {
				if(_3 < (contentHeight - naviHeight)) {
					sliderStyle.marginTop = _3 - (headerHeight - naviMarginTop) + "px";
				}
			} else {
				sliderStyle.marginTop = 0;
			}
	}
}

function startSlider(){
	var mainContent=document.getElementById("BENonFooter");
	contentHeight = mainContent.offsetHeight;
	var checker = document.getElementById("BENavi");
	naviHeight = checker.offsetHeight;
	if(!checker || !mainContent){
		return false;
	}
	sliderStyle = checker.style;
	if(naviHeight < contentHeight) {
		var _7 = window.setInterval("updateSlider()", 1000/fps);
	}
	return true;
}