在测试时候，注册填写到验证码，提交过后，总是提示验证码错误
<?php
session_start();
//注册处理界面 regcheck.php
if(isset($_POST["hidden"]) && $_POST["hidden"] == "hidden")
{
$user = trim($_POST["username"]);//trim()函数移除字符串两侧的空白字符
$psw = md5(trim($_POST["userpwd"]));
$psw_confirm = md5(trim($_POST["confirm"]));
$code = $_POST["code"];
if($user == "" || $psw == "" || $psw_confirm == "")
{
echo "<script>alert('请确认信息完整性！'); history.go(-1);</script>";
}
else if($code != $_SESSION[' ver_code']){
echo "<script>alert('验证码不正确，请重新输入！'); history.go(-1);</script>";
}
else
{
if($psw == $psw_confirm)
{
$conn = mysqli_connect("localhost","root","root"); //连接数据库,帐号密码为自己数据库的帐号密码
if(mysqli_errno($conn)){
echo mysqli_error($conn);
exit;
}
mysqli_select_db($conn,"userdb"); //选择数据库
mysqli_set_charset($conn,'utf8'); //设定字符集
$sql = "select username from user where username = '$user'"; //SQL语句
$result = mysqli_query($conn,$sql); //执行SQL语句
$num = mysqli_num_rows($result); //统计执行结果影响的行数
if($num) //如果已经存在该用户
{
echo "<script>alert('用户名已存在'); history.go(-1);</script>";
}
else //不存在当前注册用户名称
{
$ip=ip2long($_SERVER['REMOTE_ADDR']); // 把ip地址转换成整型
$time=time();
$sql_insert = "insert into `user` (`username`,`userpwd`,`createtime`,`createip`) values('" . $user . "','" . $psw ."','".$time."','".$ip."')";
$res_insert = mysqli_query($conn,$sql_insert);
if($res_insert)
{
echo "<script>alert('注册成功！');window.location.href='login.php';</script>";
}
else
{
echo "<script>alert('系统繁忙，请稍候！'); history.go(-1);</script>";
}
}
}
else
{
echo "<script>alert('密码不一致！'); history.go(-1);</script>";
}
}
}
else
{
echo "<script>alert('提交未成功！');</script>";
}
?>
