js 隐藏层随鼠标移动解决办法 _JavaScript

js 隐藏层随鼠标移动解决方法！
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script type="text/javascript" language="javascript">
	<!--当文本框的内容为空时，显示鼠标跟随效果-->
	function showlianxi(status,ev){ 
			var  e= ev||window.event; 
			var show = document.getElementById('showlianxi'); 
			var obj=e.target||e.srcElement; 
			if(fun()){
			switch(status){ 
				case 'over': 
					show.style.position='absolute'; 
					if(e.pageX){ 
						show.style.left=e.pageX+20+'px'; 
						show.style.top=e.pageY+'px'; 
						} 
					else{ 
						show.style.left=e.clientX + document.body.scrollLeft+ document.documentElement.scrollLeft+5; 
						show.style.top=e.clientY + document.body.scrollTop+ document.documentElement.scrollTop+5; 
						} 
					show.style.display='block'; 
					break; 
				case 'out': 
				show.style.display='none'; 
				break; 
			  }
			} else{
			show.style.display='none'; 
			}
		} 

      <!--判断文本框的内容是否为空-->
		function fun(){
		  var temp=document.getElementById("username").value;
		  if(temp==null||temp==''){
		     return true;
		  }else{
		     return false;
		  }
		}
	</script>
</head>
<body>
    <input type="text"    id="username" onmouseout="showlianxi('out',event)"  onmousemove="showlianxi('over',event)" />
    <div id="showlianxi" style="display:none">  
    	<a>请填写值</a>
    </div>
</body>
</html>
js 隐藏层随鼠标移动 解决办法

js 隐藏层随鼠标移动解决办法
