侧栏跟随滚动条js

1. javascript中如可控制iframe的滚动条位置

滚动条始终在来最下端自:
window.onload=function (){
document.documentElement.scrollTop=parseInt(document.body.offsetHeight)-parseInt(document.documentElement.offsetHeight)+100;
}
/*上面的加100是因为取offsetHeight的值不是很准,所以自己改到准为止*/

滚动条始终在最上端:
window.onload=function(){
document.documentElement.scrollTop=0;
}

2. 网页两侧随滚动条上下移动的图片代码

var left_img='<a target=_blank href="http://www.i263.net"><img src=one.gif border=0></a>';
var right_img='<a target=_blank href="http://www.i263.net"><img src=two.gif border=0></a>';

var delta=0.05
var collection;
function floaters() {
this.items = [];
this.addItem = function(id,x,y,content)
{
document.write('<DIV id='+id+' style="Z-INDEX: 10; POSITION: absolute; width:80px; height:60px;left:'+(typeof(x)=='string'?eval(x):x)+';top:'+(typeof(y)=='string'?eval(y):y)+'">'+content+'</DIV>');

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()
{

for(var i=0;i<collection.length;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.body.scrollLeft+followObj_x)) {
var dx=(document.body.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.body.scrollTop+followObj_y)) {
var dy=(document.body.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 = '';
}
}

var theFloaters = new floaters();
theFloaters.addItem('followDiv1','document.body.clientWidth-106',100,''+right_img+'');
theFloaters.addItem('followDiv2',6,100,''+left_img+'');
theFloaters.play();

把上面的代码保存扩展名为js的文件。然后弄两张图片。一个名字为one.gif
另一个为two.gif，三个文件放在一起。

3. js怎么实现让屏幕上的二维码可以随滚动条滚动，等二维码到浏览器最上面以后就固定在那边，求代码。

import java.awt.*;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
import javax.swing.WindowConstants;
import javax.swing.border.*;
public class jframe {
/**
* @ args
*/
public void CreateJFrame(String title) {
JFrame jf = new JFrame(title);
Container container = jf.getContentPane();
JLabel jl = new JLabel("");
jl.setHorizontalAlignment(SwingConstants.CENTER);
container.add(jl);
container.setBackground(Color.white);
jf.setVisible(true);
jf.setSize(200, 150);
jf.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
};