急求兼容IE和火狐的网站漂浮物代码！（IE9和IE5、6、7、8解析都不一样的）解决方案

急急求兼容IE和火狐的网站漂浮物代码！（IE9和IE5、6、7、8解析都不一样的）
我现有的代码只兼容IE8以下的，IE9和火狐无法兼容，求大神帮帮忙啊！！

HTML code

<div id="codefans_net" visibility: visible; border:#A3DFF7 1px solid;></div><script language="JavaScript" type="text/javascript">    var x = 50, y = 60    var xin = true, yin = true    var step = 1    var delay = 10    var obj = document.getElementById("codefans_net")    function float() {        var L = T = 0        var R = document.body.clientWidth - obj.offsetWidth        var B = document.body.clientHeight - obj.offsetHeight        obj.style.left = x + document.body.scrollLeft        obj.style.top = y + document.body.scrollTop        x = x + step * (xin ? 1 : -1)        if (x < L) { xin = true; x = L }        if (x > R) { xin = false; x = R }        y = y + step * (yin ? 1 : -1)        if (y < T) { yin = true; y = T }        if (y > B) { yin = false; y = B }    }    var itl = setInterval("float()", delay)    obj.onmouseover = function() { clearInterval(itl) }    obj.onmouseout = function() { itl = setInterval("float()", delay) }    function close_float() { obj.style.visibility = 'hidden'; }</script>