实现过程示意图
代码
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>登录</title>
<style>
.ok {
color: green;
border: 1px solid green;
}
.error {
color: red;
border: 1px solid red;
}
</style>
<script>
//校验账号的格式
function check_code() {
console.log(1);
//获取账号
var code =
document.getElementById("code").value;
//校验其格式(\w字母或数字或下划线)
var span =
document.getElementById("code_msg");
var reg = /^\w{6,10}$/;
if(reg.test(code)) {
//通过，增加ok样式
span.className = "ok";
} else {
//不通过，增加error样式
span.className = "error";
}
}
function check_pwd(){
console.log(2);
var code2 =document.getElementById("pwd").value;
var span2 =
document.getElementById("pwd_msg");
var reg2 = /^\w{6,10}$/;
if(reg2.test(code2)) {
span2.className = "ok";
} else {
span2.className = "error";
}
}
</script>
</head>
<body>
<form action="http://www.tmooc.cn">
<p>
账号：
<input type="text" id="code" onblur="check_code()"/>
<span id="code_msg">6-10位字母、数字、下划线</span>
</p>
<p>
密码：
<input type="text" id="pwd" onblur="check_pwd()" />
<span id="pwd_msg">8-20位字母、数字、下划线</span>
</p>
<p><input type="submit" value="登录"/></p>
</form>
</body>
</html>
