prepareSlideshow函数

function prepareSlideshow() {
if (!document.getElementsByTagName) return false;
if (!document.getElementById) return false;
if (!document.getElementById("linklist")) return false;
var slideshow=document.createElement("div");
slideshow.setAttribute("id","slideshow");
var preview=document.createElement("img");
preview.setAttribute("src","images/topics.gif");
preview.setAttribute("alt","building blocks of web design");
preview.setAttribute("id","preview");
slideshow.appendChild(preview);
var list=document.getElementById("linklist");
insertAfter(slideshow,list);
var links=list.getElementsByTagName("a");
links[0].onmouseover=function(){
moveElement("preview",-100,0,10);
}
links[1].onmouseover=function(){
moveElement("preview",-200,0,10);
}
links[2].onmouseover=function(){
moveElement("preview",-300,0,10);
}
}
addLoadEvent(prepareSlideshow);

已经平稳退化，把div里的属性元素，id元素全部放在了JavaScript里面，退化的更彻底。