Insert impossibile aiutoooo!!!

[chopper_read]

Questo codice viene richiamato da una pagina html con un form e dei campi testo e radio...
..le ho provate di tutti i colori nn riesco ad ottenere inserimenti validi nel database..o campi vuoti o niente...aiuto x favore!!

<?php
//require "database.php";
$dbhost = 'localhost';
$dbusername = 'root';
$dbpasswd = '';
$database_name = 'factory';

$connection = mysql_connect("$dbhost","$dbusername","$dbpasswd")
    or die ("Couldn't connect to server.");

$db = mysql_select_db("$database_name", $connection)
    or die("Couldn't select database.");
        
require "utility.php";

// Convert to simple variables
$name = $_POST['name'];
$surname = $_POST['surname'];
$birthday = $_POST['birthday'];
$address = $_POST['address'];
$cf = $_POST['cf'];
$profit = $_POST['profit'];
$action = $_POST['Question1'];

//echo $action;      

function add_user() {
    
    $sql = sprintf("INSERT INTO `factory`.`dependent` (`name`, `surname`, `birthday`, `address`, `cf`, `profit`) VALUES ('%s', '%s', '%s', '%s', '%s', '%d');",
                   mysql_real_escape_string($name,$connection),
                   mysql_real_escape_string($surname,$connection),
                   mysql_real_escape_string($birthday,$connection),
                   mysql_real_escape_string($address,$connection),
                   mysql_real_escape_string($cf,$connection),
                   $profit);
    $result = mysql_query($sql,$connection);
    if(mysql_num_rows($result)>0) {
        echo $_POST[0]." ".$_POST[1]." dependent added into database";
    } else {
        echo mysql_error();
    }
    
}

function remove_user(){
        
    $sql = sprintf("DELETE FROM `dependent` WHERE `dependent`.`cf` = '%s';",
                   mysql_real_escape_string($cf,$connection));
    $result = mysql_query($sql);
    
    if(mysql_num_rows($result)>0) {
        echo $_POST['name']." ".$_POST['surname']." removed from database";
    } else {
        echo mysql_error();
    }
}

if ($action == "add") {
    add_user();
} else {
    remove_user();
    
}

$success = mysql_close($connection);

?>

[chopper_read]

Warning: mysql_real_escape_string() expects parameter 2 to be resource, null given in C:\xampp\htdocs\Factory\handleuser.php on line 29

Warning: mysql_real_escape_string() expects parameter 2 to be resource, null given in C:\xampp\htdocs\Factory\handleuser.php on line 30

Warning: mysql_real_escape_string() expects parameter 2 to be resource, null given in C:\xampp\htdocs\Factory\handleuser.php on line 31

Warning: mysql_real_escape_string() expects parameter 2 to be resource, null given in C:\xampp\htdocs\Factory\handleuser.php on line 32

Warning: mysql_real_escape_string() expects parameter 2 to be resource, null given in C:\xampp\htdocs\Factory\handleuser.php on line 33

Warning: mysql_query(): supplied argument is not a valid MySQL-Link resource in C:\xampp\htdocs\Factory\handleuser.php on line 35

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in C:\xampp\htdocs\Factory\handleuser.php on line 36