Javascript 检测、添加、移除样式(className)函数代码

<script type="text/javascript"> 
// 说明：添加、移除、检测 className 
function hasClass(element, className) { 
var reg = new RegExp('(\\s|^)'+className+'(\\s|$)'); 
return element.className.match(reg); 
} 
function addClass(element, className) { 
if (!this.hasClass(element, className)) 
{ 
element.className += " "+className; 
} 
} 
function removeClass(element, className) { 
if (hasClass(element, className)) { 
var reg = new RegExp('(\\s|^)'+className+'(\\s|$)'); 
element.className = element.className.replace(reg,' '); 
} 
} 
</script>