浮动层固定位置的方法

1. var $ = document.getElementById;
2. var $$ = document.documentElement;
3. function fixDiv(id){
4.     $(id).style.top = ($$.scrollTop + $$.clientHeight - $(id).clientHeight - 20) + "px";
5.     setTimeout("fixDiv('newYear')",2);
6. }
7. fixDiv('newYear');