var divobj = document.createElement("div");
divobj.innerHTML = "";
var firstNode = document.body.firstChild;
document.body.insertBefore(divobj,firstNode);
var x = 50,y = 50;
var xin = true, yin = true; //鍒ゆ柇灞傜殑X鍧愭爣鍜孻鍧愭爣鏄惁鍦ㄥ湪鎺у埗鑼冨洿涔嬪唴锛寈in涓虹湡鏄眰鍚戝彸绉诲姩锛屽惁鍒欏悜宸︼紱yin涓虹湡鏄眰鍚戜笅绉诲姩锛屽惁鍒欏悜涓
var step = 1; //灞傜Щ鍔ㄧ殑姝ラ暱锛屽艰秺澶хЩ鍔ㄩ熷害瓒婂揩
var delay = 10; //灞傜Щ鍔ㄧ殑鏃堕棿闂撮殧,鍗曚綅涓烘绉掞紝鍊艰秺灏忕Щ鍔ㄩ熷害瓒婂揩
var obj=document.getElementById("tijiao"); //鎹曡幏id涓篴d鐨勫眰浣滀负婕傛诞鐩爣
function floatAD() {
var L=T=10;
var R= document.body.clientWidth-obj.offsetWidth-10; //灞傜Щ鍔ㄧ殑鍙宠竟鐣
var B= document.body.clientHeight-obj.offsetHeight; //灞傜Щ鍔ㄧ殑涓嬭竟鐣
obj.style.left = x + document.body.scrollLeft; //鏇存柊灞傜殑X鍧愭爣锛屽疄鐜癤杞存柟鍚戜笂鐨勮繍鍔紱document.body.scrollLeft涓烘枃妗ｅ尯鍩熺殑婊氬姩鏉″悜鍙虫媺鐨勮窛绂伙紝浠ヤ繚璇佸湪婊氬姩鏉″彸鎷夋椂灞備粛鍦ㄥ彲瑙佽寖鍥村唴
obj.style.top = y + document.body.scrollTop; //鏇存柊灞傜殑Y鍧愭爣锛屽疄鐜癥杞存柟鍚戜笂鐨勮繍鍔紱document.body.scrollTop涓烘枃妗ｅ尯鍩熺殑婊氬姩鏉″悜涓嬫媺鐨勮窛绂伙紝浠ヤ繚璇佸湪婊氬姩鏉′笅鎷夋椂灞備粛鍦ㄥ彲瑙佽寖鍥村唴
x = x + step*(xin?1:-1); //閫氳繃鍒ゆ柇灞傜殑鑼冨洿鍐冲畾灞傚湪X杞翠笂鐨勮繍鍔ㄦ柟鍚
if (x < L) { xin = true; x = L;} //灞傝秴鍑哄乏杈圭晫鏃剁殑澶勭悊
if (x > R){ xin = false; x = R;} //灞傝秴鍑哄彸杈圭晫鏃剁殑澶勭悊
y = y + step*(yin?1:-1); //閫氳繃鍒ゆ柇灞傜殑鑼冨洿鍐冲畾灞傚湪Y杞翠笂鐨勮繍鍔ㄦ柟鍚
if (y < T) { yin = true; y = T ;} //灞傝秴鍑轰笂杈圭晫鏃剁殑澶勭悊
if (y > B) { yin = false; y = B; } //灞傝秴鍑轰笅杈圭晫鏃剁殑澶勭悊
}
var itl= setInterval("floatAD()", delay); //姣廳elay绉掓墽琛屼竴娆loatAD鍑芥暟
obj.onmouseover=function(){clearInterval(itl);}; //灞傚湪榧犳爣绉讳笂鏃舵竻闄や笂闈㈢殑闂撮殧浜嬩欢锛屽疄鐜板眰鍦ㄧ殑榧犳爣绉讳笂鏃跺仠姝㈣繍鍔ㄧ殑鏁堟灉
obj.onmouseout=function(){itl=setInterval("floatAD()", delay);}; //灞傚湪榧犳爣绉诲紑鏃跺紑濮嬮棿闅斾簨浠讹紝瀹炵幇灞傚湪鐨勯紶鏍囩Щ寮鏃剁户缁繍鍔ㄧ殑鏁堟灉