## scroll封装 ``` /*滚动函数*/ function scroll(){ if(window.pageYOffset!=null){ return { left:window.pageYOffset, top:window.pageYOffset } } else if(document.compatMode == "CSS1Compat"){ return { left:document.documentElement.scrollLeft, top:document.documentElement.scrollTop } } return { left:document.body.scrollLeft, top:document.body.scrollTop } } ```