最近几天做了一个项目，原来是用css3动画做的，由于不兼容IE，改成用js做了，特此分享给大家，供大家参考，代码有bug欢迎提出，写的不好还请见谅!
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"><head><meta http-equiv="Content-Type" content="text/html;charset=UTF-8" /><title>float left and top</title><style type="text/css">.w1000{position:relative;width:1000px;margin:0 auto;}.positionpub{position:absolute;}.positionpub p{width:50px;height:50px;background:#333;color:#fff;line-height:50px;text-align:center;position:absolute;}.ad_Float{top:50px;left:50px;}.ad_Float1{top:150px;left:250px;}.ad_Float2{top:250px;left:450px;}</style></head><body><div><div><p id="ad_Float">left</p></div><div><p id="ad_Float1">right</p></div><div><p id="ad_Float2">down</p></div></div><script type="text/javascript">var x = 0, y = 0 , x1 = 0;var xin = true, yin = true;var step = 1,step2 = 2;var delay = 10;var obj = document.getElementById("ad_Float");var obj1 = document.getElementById("ad_Float1");var obj2 = document.getElementById("ad_Float2");function ad_Float() {var L = 0;var R = 100;obj.style.left = x + document.documentElement.scrollLeft + "px";x = x + step * (xin ? 1 : -1);if (x < L) {xin = true;x = L;}if (x > R) {xin = false;x = R;}};function ad_Float1() {var L1 = 0;var R1 = 100;obj1.style.left = x1 + document.documentElement.scrollLeft + "px";x1 = x1 + step * (xin ? 1 : -1);if (x1 < L1) {xin = true;x1 = L1;}if (x1 > R1) {xin = false;x1 = R1;}};function ad_Float2() {var T = 0;var B = 150;obj2.style.top = y + document.documentElement.scrollTop + "px";y = y + step2 * (yin ? 1 : -1);if (y < T) {yin = true;y = T;}if (y > B) {yin = false;y = B;}};var itl = setInterval("ad_Float()", delay);var itl1 = setInterval("ad_Float1()", delay);var itl2 = setInterval("ad_Float2()", delay);</script></body></html> 代码到此结束了，希望对大家有所帮助！