console 命令行工具 X clear
console
 <!-- edu 15_ 6_ 1.html -->

<!doctype html>

 <html lang="en">

<head>

<meta charset="UTF-8">

<title>用户注册页面</title>

<style type="text/css">

strong {color :red; font-style:bolder; }

fieldset {width:560px; height: 186px;padding:0px 50px; }

#button {margin:10px 20px;}

</style>

<script type="text/javascript">

 function $(id) {return document.getElementById(id); }

function checkReg()
{var username=$ ("myname") . value;

var pwd=$ ("mypwd1") .value;

var pwdConfirm=$ ("mypwd2") . value;

var checkright=true; 

if (username=="" || pwd==""){

//两者中有一个为空

alert ("请确认用户名和密码输入是否正确! ! ");checkright=false;

}else//不为空，再判断用户名和密码的长度合法性
{
if (username. length<6){

alert("用户名长度太短，至少6个字符! ! ");checkright=false;

}else if (pwd. length<6) {

alert ("密码长度太短，至少6个字符! ! ");checkright=false;

}else if (pwd!=pwdConfirm) {

alert ("两次输入的密码必须一致! ! ");checkright=false;

}else{

checkright=true; }

return checkright;
}

function clearInfo(){

var flag = confirm("确认要重置数据吗? "); if (flag==true)

$("myname") .value = "";


$ ("mypwd1") .value = "";

$ ("mypwd2") .value = "";
}
}
</script>

</head>

<body>

<form action="regsuccess. html" method="get" onSubmit="return

checkReg()" onReset="clearInfo()">

<fieldset>

<legend al ign="center" >新用户注册</legend><br>

<div>

<label >用&nbsp;户&nbsp;名: </label>

<input type="text" name= "myname" id= "myname">

<strong> (用户名要大于6位) </strong><br>

<label>登录密码: </label>

<input type="password" name= "mypwd1" id="mypwd1"> <strong> (密码要大于6位)</strong><br>

<label>密码确认: </label>

<input type="password" name= "mypwd2" id= "mypwd2"><br>

<input id="button" type="submit" value="用户注册" >

<input id="button" type="reset" value="重置">

</div>

</fieldset>

</form>

</body>

</html>