function checkRegisterForm() {
    var user_name = document.getElementById('username');
    var re = /^\w{3,10}$/;
    if (re.test(user_name.value) === false) {
        alert('用户名3-10位的字母或数字');
        return false;
    }

    var user_pwd = document.getElementById('password');
    if (user_pwd.value.length < 6 || user_pwd.value.length > 20) {
        alert('密码长度6-20位');
        return false;
    }

    var user_pwd2 = document.getElementById('password-2');
    if (user_pwd.value !== user_pwd2.value) {
        alert('2次密码不同')
        return false;
    }

    return true;
}