在php中启用错误，不会显示某些错误

I have certain problems with error reporting in php. I know that it doesn't report them by default, so i tried every solution i found online.

I used the following code inside my php file:

error_reporting(E_ALL | E_STRICT);
ini_set("display_errors", 1);

And i also edited the php.ini file. Right now it looks like this:

; display_errors
;   Default Value: On
;   Development Value: On
;   Production Value: On

; display_startup_errors
;   Default Value: On
;   Development Value: On
;   Production Value: On

; error_reporting
;   Default Value: E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED
;   Development Value: E_ALL 
;   Production Value: E_ALL & ~E_DEPRECATED & ~E_STRICT

It works up to a certain point. Errors like syntax errors, for example a missing semicolons show, but when i fix them in my code, i get once again the blank screen. So i believe certain errors still don't show.

The code causing this is a simple php registration form:

<?php

error_reporting(E_ALL | E_STRICT);
ini_set("display_errors", 1);

define('DB_SERVER', 'localhost');
define('DB_USERNAME','root');
define('DB_PASSWORD','');
define('DB_DATABASE', 'maindatabase');

$db = mysqli_connect(DB_SERVER,DB_USERNAME,DB_PASSWORD,DB_DATABASE);




 function NewUser()
{
    $fname = $_POST['fname'];          
    $lname = $_POST['lname']; 
    $email = $_POST['email'];
    $username = $_POST['username'];    
    $password =  $_POST['password'];   

    $fname = mysqli_real_escape_string($db, $fname);
    $lname = mysqli_real_escape_string($db, $lname);
    $email = mysqli_real_escape_string($db, $email);
    $username = mysqli_real_escape_string($db, $username);
    $password = mysqli_real_escape_string($db, $password);
    $query = mysqli_query($db, "INSERT INTO users (Username, Password, FirstName, LastName, Email) VALUES ('$username','$password','$fname','$lname','$email')"); 

    if($query)
    {
    echo "sucess";
    }
}




if(isset($_POST['submit']))
{
        NewUser();
}

?>

I guess there is some sort of fatal error not showing? What would that be?

Basically what i am asking is what type of error (in the above code and in general) is not displayed, when syntax errors do?

Can someone please give me some perspective, i have tried everything i found on the internet and still nothing.

I am using xampp, on windows 7.

If the error causes a fatal compile-time error, then your script will never even execute, meaning the ini_set() call will never occur.

You need to set them at the php.ini level, so they'll be in effect when PHP starts up, not AFTER your script has (maybe) started executing.