/*
 * Affiliated function
 * @author : Minuery
*/

/*************************
 鍔熻兘鍚嶇О:杩斿洖椤堕儴
 鍙傛暟璇存槑:btnId浠绘剰鍏冪礌ID鍙?Time鏃堕棿锛堝娉?鏁板瓧瓒婂ぇ瓒婃參锛
*************************/
backTop=function (btnId,Time){
	var btn=document.getElementById(btnId);
	var scrollTop = document.documentElement.scrollTop || document.body.scrollTop;
	window.onscroll=set;
	btn.onclick=function (){
		btn.style.opacity="0.5";
		window.onscroll=null;
		this.timer=setInterval(function(){
		    scrollTop = document.documentElement.scrollTop || document.body.scrollTop;
			scrollTop-=Math.ceil(scrollTop*0.1);
			if(scrollTop==0) clearInterval(btn.timer,window.onscroll=set);
			if (document.documentElement.scrollTop > 0) document.documentElement.scrollTop=scrollTop;
			if (document.body.scrollTop > 0) document.body.scrollTop=scrollTop;
		},Time);
	};
	function set(){
	    scrollTop = document.documentElement.scrollTop || document.body.scrollTop;
	    btn.style.opacity=scrollTop?'1':"0.5";
	}
};