Ajax显示实时数据时的表格风格设置

 

代码
<style>
.button{ font-style:italic;left:400px;}
</style>
<input type="button" onclick="clickButton()">
<script language="javascript">
function clickButton()
{
var str="";
//这里想通过script获得class.button中的cssText
}
</script>

怎样通过script获得class.button中的cssText
结果：str="font-style:italic;left:400px;"

IE浏览器中：<element>.style.cssText="font-weight:bold;";

非IE浏览器中：<element>.setAttribute("style","font-weight:bold;");

                         <element>.setAttribute("class","new-ClassName");