怎么写这个样式

<style type="text/css">
.a{ background-color:#00cc00; height:100px; width:100px}
.b{background-color:#cccccc}
</style><body>
<div id='test' class='a'></div>
</body>我希望的效果是
当时鼠标移动到div上的时候 
div的 className变成 "a b"
鼠标离开div的时候
div的className变成"a"怎么写？

解决方案 »

  1.   

    <script>
    window.onload=function(){
        var div=document.getElementById("test");
        div.onmouseover=function(){this.className="a";};
        div.onmouseout=function(){this.className="b";};
    }
    </script>
      

  2.   

    <script>
    window.onload=function(){
        var div=document.getElementById("test");
        div.onmouseover=function(){this.className="a";};
        div.onmouseout=function(){this.className="b";};
    }
    </script>
    <style type="text/css"> 
    .a{ background-color:#00cc00; height:100px; width:100px} 
    .b{ background-color:#cccccc; height:100px; width:100px} 
    </style> <body> 
    <div id='test' class='a'> </div> 
    </body> 
      

  3.   

    不对噢  
    鼠标放上去的时候是样式变成 "a b"       就象jq里面的addclass一样
    鼠标移开的时候 变成"a"                 象removeClass一样
      

  4.   


    window.onload=function(){
        var div=document.getElementById("test");
        div.onmouseover=function(){this.className="a b";};
        div.onmouseout=function(){this.className="b";};
    }注意样式b要写在a的后面
      

  5.   

     div.onmouseout=function(){this.className="a";};
      

  6.   

    ls的也不算
    这就是直接附直
    a,b是未知的 不能这么写
      

  7.   

    什么意思？不是未知的哪来的样式？想jq那样的网上很多呢http://www.codebit.cn/pub/html/javascript/tutorial/add_remove_class/
      

  8.   


    addClass: function(value) {
                if (jQuery.isFunction(value)) {
                    return this.each(function(i) {
                        var self = jQuery(this);
                        self.addClass(value.call(this, i, self.attr("class")));
                    });
                }            if (value && typeof value === "string") {
                    var classNames = (value || "").split(rspace);                for (var i = 0, l = this.length; i < l; i++) {
                        var elem = this[i];                    if (elem.nodeType === 1) {
                            if (!elem.className) {
                                elem.className = value;                        } else {
                                var className = " " + elem.className + " ";
                                for (var c = 0, cl = classNames.length; c < cl; c++) {
                                    if (className.indexOf(" " + classNames[c] + " ") < 0) {
                                        elem.className += " " + classNames[c];
                                    }
                                }
                            }
                        }
                    }
                }            return this;
            }