我是新手能帮我解释一下这句的意思吗
<td id= "imgmenu1 " class= "menu_title " onmouseover= "this.className= 'menu_title2 '; " onclick= "showsubmenu(1) " onmouseout= "this.className= 'menu_title '; " style= "cursor:hand " background=image/menudown.gif height= "25 ">
<span> 系统管理 </span> </td>
[解决办法]
onmouseover= "this.className= 'menu_title2 '; " 鼠标移入后调用menu_title2
onclick= "showsubmenu(1) " 鼠标点击后调用一个js函数
onmouseout= "this.className= 'menu_title ' 鼠标移开后调用menu_title
