JavaScript实现鼠标悬浮文字弹出提示层

<!doctype html> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
 <title>TEST</title> 
</head> 
<style type="text/css"> 
 body{ 
 position: relative; 
 } 
 #inform{ 
 position: absolute; 
 top: 20px; 
 width: 350px; 
 max-height: 250px; /* 设置最大高度，当高度达到此值时出现滚动条 */ 
 z-index: 10; 
 background-color: #E0E5E5; 
 overflow: auto; /* 自动添加滚动条 */ 
 box-shadow:0px 0px 10px #000; /* 外阴影 */ 
 display: none; /* 默认隐藏 */ 
 } 
 #informTable{ 
 table-layout:fixed; /* 用于实现表格td自动换行的部分代码*/ 
 width: 325px; 
 } 
 
 #informTable tr td{ 
 width: 325px; 
 height:30px; 
 font-size: 16px; 
 font-family: Georgia; 
 color: #555555; 
 word-wrap:break-word; /*自动换行*/ 
 padding: 0 0 0 0; 
 } 
 #informTable tr td:hover{ 
 background-color: #D9D9D9; 
 } 
 #inform hr{ 
 border:1; 
 width: 325px; 
 margin-bottom: 0px; 
 } 
 
</style> 
<script type="text/javascript"> 
 //显示悬浮层 
 function showInform(){ 
 document.getElementById("inform").style.display='block'; 
 // document.getElementById("inform").css("display","block"); 
 } 
 //隐藏悬浮层 
 function hiddenInform(event){ 
 var informDiv = document.getElementById('inform'); 
 var x=event.clientX; 
 var y=event.clientY; 
 var divx1 = informDiv.offsetLeft; 
 var divy1 = informDiv.offsetTop; 
 var divx2 = informDiv.offsetLeft + informDiv.offsetWidth; 
 var divy2 = informDiv.offsetTop + informDiv.offsetHeight; 
 if( x < divx1 || x > divx2 || y < divy1 || y > divy2){ 
 document.getElementById('inform').style.display='none'; 
 } 
 
 } 
 
 
</script> 
<body> 
 <a id="btn" onMouseOver="javascript:showInform();" onMouseOut="hiddenInform()"> 
 警告消息 
 </a> 
 <div id="inform" onMouseOver="javascript:showInform();" onMouseOut="hiddenInform(event)"> 
 <table id="informTable"> 
 <tr> 
 <td> 
  编号5005车辆发车间隔异常 
  <hr/> 
 </td> 
 </tr> 
 <tr> 
 <td> 
  编号5005车辆发车间隔异常 
  <hr/> 
 </td> 
 </tr> 
 <tr> 
 <td> 
  编号5005车辆发车间隔异常 
  <hr/> 
 </td> 
 </tr> 
 <tr> 
 <td> 
  编号5005车辆发车间隔异常 
  <hr/> 
 </td> 
 </tr> 
 <tr> 
 <td> 
  编号5005车辆发车间隔异常 
  <hr/> 
 </td> 
 </tr> 
 <tr> 
 <td> 
  编号5005车辆发车间隔异常 
  <hr/> 
 </td> 
 </tr> 
 <tr> 
 <td> 
  编号5005车辆发车间隔异常 
  <hr/> 
 </td> 
 </tr> 
 <tr> 
 <td> 
  编号5005车辆发车间隔异常 
  <hr/> 
 </td> 
 </tr> 
 </table> 
 </div> 
</body> 
</html>