var options  = "";

function ancScroll(url){

	var scroller = (function() {
		var c = $.extend({
			easing:100,
			step:30,
			fps:60,
			fragment:''
		}, options);
		c.ms = Math.floor(1000/c.fps);
		var timerId;
		var param = {
			stepCount:0,
			startY:0,
			endY:0,
			lastY:0
		};
		//スクロール中に実行されるfunction
		function move() {
			if (param.stepCount == c.step) {
				//スクロール終了時
				setFragment(param.hrefdata.absolutePath);
				window.scrollTo(getCurrentX(), param.endY);
			} else if (param.lastY == getCurrentY()) {
				//通常スクロール時
				param.stepCount++;
				window.scrollTo(getCurrentX(), getEasingY());
				param.lastY = getEasingY();
				timerId = setTimeout(move, c.ms); 
			} else {
				//キャンセル発生
				if (getCurrentY()+getViewportHeight() == getDocumentHeight()) {
					//画面下のためスクロール終了
					setFragment(param.hrefdata.absolutePath);
				}
			}
		}
		function setFragment(path){
			location.href = path
		}
		function getCurrentY() {
			return document.body.scrollTop  || document.documentElement.scrollTop;
		}
		function getCurrentX() {
			return document.body.scrollLeft  || document.documentElement.scrollLeft;
		}
		function getDocumentHeight(){
			return document.documentElement.scrollHeight || document.body.scrollHeight;
		}
		function getViewportHeight(){
			return (!$.browser.safari && !$.browser.opera) ? document.documentElement.clientHeight || document.body.clientHeight || document.body.scrollHeight : window.innerHeight;
		}
		function getEasingY() {
			return Math.floor(getEasing(param.startY, param.endY, param.stepCount, c.step, c.easing));
		}
		function getEasing(start, end, stepCount, step, easing) {
			var s = stepCount / step;
			return (end - start) * (s + easing / (100 * Math.PI) * Math.sin(Math.PI * s)) + start;
		}
		return {
			set: function(options) {
				this.stop();
				if (options.startY == undefined) options.startY = getCurrentY();
				param = $.extend(param, options);
				param.lastY = param.startY;
				timerId = setTimeout(move, c.ms); 
			},
			stop: function(){
				clearTimeout(timerId);
				param.stepCount = 0;
			}
		};
	})();
	
	
	var hrefdata = new Object();
	hrefdata.fragment = url;
	hrefdata.absolutePath = url;
	var target = $(hrefdata.fragment);
	
	

	if (target.length) {
		scroller.set({
			endY: target.offset().top,
			hrefdata: hrefdata
		});
		return false;
	}


}