<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script type="text/javascript">
function show(id,info){
var el = document.getElementById("user").value;
var a = document.getElementById(id+"Name");
if(el==""){
a.style.display="inline-block";
a.innerHTML=info;
}else{
a.style.display="none";
}
}
onblur="check('user','用户名不能为空')"
function check(id,info){
var el = document.getElementById("user").value;
var a = document.getElementById(id+"Name");
if(el==""){
a.style.display="inline-block";
a.innerHTML=info;
}else{
a.style.display="none";
}
}
</script>
</head>
<body>
<table cellspacing="0" cellpadding="0">
<tr>
<td>用户名</td>
<td>
<input type="text" id="user" onfocus="show('user','用户名必填')" onblur="check('user','用户名不能为空')"/><span id="userName" ></span>
</td>
</tr>
<tr>
<td>密码</td>
<td>
<input type="password" id="password" onfocus="show('password','密码必填')" onblur="check('password','密码不能为空')"/><span id="passwordName" ></span>
</td>
</tr>
<tr>
<td>确认密码</td>
<td>
<input type="password" id="passwordAgain" onfocus="show('passwordAgain','密码必填')" onblur="check('passwordAgain','密码不能为空')"/><span id="passwordAgainName" ></span>
</td>
</tr>
</table>
</body>
</html>