text: var getBox = function(el) {
  	return el.getBoundingClientRect();
  }
  var getElementPos = function(el) {
  	var x= 0, y =0;
  	for(var e = el;e != null; e= e.offsetParent) {
  		x += e.offsetLeft;
  		y += e.offsetTop;
  	}
  	for(var e = el.parentNode;e != null && e.nodeType == 1;e = e.parentNode) {
  		x -= e.scrollLeft;
  		y -= e.scrollTop;
  	}
  	return {
  		x,
  		y
  	}
  }
  
  var getScroll = function() {
  	var w = window;
  	if(w.pageXOffset != null) {
  		return {
  			x: w.pageXOffset,
  			y: w.pageYOffset
  		}
  	}
  
  	var d = w.document;
  	if(document.compatMode == "CSS1Compat") {
  		return {
  			x: d.documentElement.scrollLeft,
  			y: d.documentElement.scrollTop
  		}
  	}
  
  	return {
  		x: d.body.scrollLeft,
  		y: d.body.scrollTop
  	}
  }
  var getViewportSize = function() {
  	var w = window;
  	if(w.innerWidth != null) {
  		return {
  			w: w.innerWidth,
  			h: w.innerHeight
  		}
  	}
  
  	var d = w.document;
  	if(document.compatMode == "CSS1Compat") {
  		return {
  			x: d.documentElement.clientWidth,
  			y: d.documentElement.clientHeight
  		}
  	}
  
  	return {
  		x: d.body.clientWidth,
  		y: d.body.clientHeight
  	}
  }
  
  var gotoTop = function () {
  	var h= getScrollTop(),
  	  	i=0,
  	  	time = 300,
  	  	to=0;
  	var tid = setInterval(()=>{
  
  	 		let height = h-(h/(time/20))*i;
  	  	if(height > to) {
  	  		window.scrollTo(0,height);
  	  	} else {
  	  		window.scrollTo(0,0);
  	  		clearInterval(tid);
  	  	}
  	  	i++;
  	 },20);
  }
  var getScrollTop = function(){
  		　　var scrollTop = 0, bodyScrollTop = 0, documentScrollTop = 0;
  		　　if(document.body){
  		　　　　bodyScrollTop = document.body.scrollTop;
  		　　}
  		　　if(document.documentElement){
  		　　　　documentScrollTop = document.documentElement.scrollTop;
  		　　}
  		　　scrollTop = (bodyScrollTop - documentScrollTop > 0) ? bodyScrollTop : documentScrollTop;
  		　　return scrollTop;
  };
  export {
  	getBox,
  	getElementPos,
  	getScroll,
  	getViewportSize,
  	gotoTop
  }