During the test, when registering, fill in the verification code. After submission, it always prompts that the verification code is wrong.

Question

<?php

session_start();

//Registration processing interface regcheck.php

if(isset($_POST["hidden"]) && $_POST["hidden"] == "hidden")

{

$user = trim($_POST["username"]);//trim() function removes strings White space characters on both sides

$psw = md5(trim($_POST["userpwd"]));

$psw_confirm = md5(trim($_POST["confirm"])) ;

$code = $_POST["code"];

if($user == "" || $psw == "" || $psw_confirm == "")

{

echo "<script>alert('Please confirm the integrity of the information!'); history.go(-1);</script>";

}

else if($code != $_SESSION[' ver_code']){

echo "<script>alert('The verification code is incorrect, please re-enter!') ; history.go(-1);</script>";

}

else

{

if($psw == $ psw_confirm)

{

$conn = mysqli_connect("localhost","root","root"); //Connect to the database, the account password is the account password of your own database

if(mysqli_errno($conn)){

echo mysqli_error($conn);

exit;

}

mysqli_select_db($conn, "userdb"); //Select database

mysqli_set_charset($conn,'utf8'); //Set character set

$sql = "select username from user where username = '$ user'"; //SQL statement

$result = mysqli_query($conn,$sql); //Execute SQL statement

$num = mysqli_num_rows($result); //Statistical execution The number of rows affected by the result

if($num) //If the user already exists

{

echo "<script>alert( 'Username already exists'); history.go(-1);</script>";

}

else //The current registered user name does not exist

{

$ip=ip2long($_SERVER['REMOTE_ADDR']); // Convert the ip address into an integer

$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('Registration successful! ');window.location.href='login.php';</script>";

}

else

{

echo "<script>alert('The system is busy, please wait!'); history.go(-1);</script>";

}

}

}

else

{

echo "<script>alert('Password inconsistent!'); history.go( -1);</script>";

}

}

}

else

{

echo "<script>alert('Submission failed!');</script>";

}

?>

Answer 1

Print $code and $_SESSION[' ver_code'] respectively to see if there is any data