t检查用户注册信息是否正确,在以下情况不满足时报错并阻止提交表单:
用户名必须是3-10位英文字母或数字;
口令必须是6-20位;
两次输入口令必须一致。
<form id="test-register" action="#" target="_blank" onsubmit="return checkRegisterForm()">
<p id="test-error" style="color:red"></p>
<p>
用户名: <input type="text" id="username" name="username">
</p>
<p>
口令: <input type="password" id="password" name="password">
</p>
<p>
重复口令: <input type="password" id="password-2">
</p>
<p>
<button type="submit">提交</button> <button type="reset">重置</button>
</p>
</form>
'use strict';
var checkRegisterForm = function () {
var username = document.getElementById('username');
var password = document.getElementById('password');
var password2 = document.getElementById('password-2');
var re_username = /^\w{3,10}$/;
var re_passwd = /.{6,20}/;
if (!re_username.test(username.value)) {
alert("用户名长度须为3-10位字母或数字");
return false;
}
if (!re_passwd.test(password.value)) {
alert("口令必须是6-20位");
return false;
}
if (password.value != password2.value) {
alert("两次输入口令不一致");
return false;
}
return true;
}
// 测试:
;(function () {
window.testFormHandler = checkRegisterForm;
var form = document.getElementById('test-register');
if (form.dispatchEvent) {
var event = new Event('submit', {
bubbles: true,
cancelable: true
});
form.dispatchEvent(event);
} else {
form.fireEvent('onsubmit');
}
})();