javascript一段左右两边随屏滚动的代码_javascript技巧

var delta=0.15
var collection;
var closeB=false;
function floaters(){
this.items=[];
this.addItem=function (id,x,y,content)
{
document.write(''+content+'');
var newItem={
};
newItem.object=document.getElementById(id);
newItem.x=x;
newItem.y=y;
this.items[this.items.length]=newItem;
}
this.play=function ()
{
collection=this.items
setInterval('play()',10);
}
}

function play()
{
if(screen.width<=8||closeB)
{
for(var i=0;i{
collection[i].object.style.display='none';
}
return ;
}
for(var i=0;i{
var followObj=collection[i].object;
var followObj_x=(typeof (collection[i].x)=='string'?eval(collection[i].x):collection[i].x);
var followObj_y=(typeof (collection[i].y)=='string'?eval(collection[i].y):collection[i].y);
if(followObj.offsetLeft!=(document.documentElement.scrollLeft+followObj_x))
{
var dx=(document.documentElement.scrollLeft+followObj_x-followObj.offsetLeft)*delta;
dx=(dx>0?1:-1)*Math.ceil(Math.abs(dx));
followObj.style.left=followObj.offsetLeft+dx;
}
if(followObj.offsetTop!=(document.documentElement.scrollTop+followObj_y))
{
var dy=(document.documentElement.scrollTop+followObj_y-followObj.offsetTop)*delta;
dy=(dy>0?1:-1)*Math.ceil(Math.abs(dy));
followObj.style.top=followObj.offsetTop+dy;
}
followObj.style.display='';
}
}

function closeBanner()
{
closeB=true;
return ;
}
var theFloaters=new floaters();
//
theFloaters.addItem('followDiv2',22,238,'

');
theFloaters.addItem('followDiv1','document.body.clientWidth-100',238,'

');
theFloaters.play();

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