Problema con file di registrazione in php, non funziona e dà continui errori

[Hyder_]

Ciao a tutti ho un problema con il mio file regverify.php

Inanzitutto eseguendo una query insert into, non viene riconosciuta e quindi significa che non sono connesso.

Infatti:

include("functions_custom.php");include("register.php");include("config.php");
$link = mysql_connect('localhost', $db_user, $db_psw);if (!$link) {    die('Not connected : ' . mysql_error());}
// make foo the current db$db_selected = mysql_select_db($db_name, $link);if (!$db_selected) {    die ('Can\'t use '.$db_name.' : ' . mysql_error());}
$sql = "INSERT INTO `users`(`username`) VALUES (\'ciao\')"; /* Questa query non va.. */ 

Dal file config.php ottengo le informazioni necessarie per il mio script di connessione (ovviamente non vi mostro le credenziali)

$host = "localhost"; $db_user = "user"; $db_psw = "password"; $db_name = "my_database"; 

Poi ho un altro problema:

Dovrei controllare se l'username immesso dall'utente durante la registrazione è già esistente, stessa cosa farei con l'email, avvertendo con un alert personalizzato.

Ma non funziona, qualcosa sbaglio ed infatti in questo codice completo:

<?php ini_set("display_errors", 1); error_reporting(E_ALL); ?>
<?php

/***   * MyPCMS  (My Powerful Content Management System) ** Version 0.0.3 beta standard** About team in > "http://mypcms.com/about/team"***/


include("functions_custom.php");include("register.php");include("config.php");
$link = mysql_connect('localhost', $db_user, $db_psw);if (!$link) {    die('Not connected : ' . mysql_error());}
// make foo the current db$db_selected = mysql_select_db($db_name, $link);if (!$db_selected) {    die ('Can\'t use '.$db_name.' : ' . mysql_error());}
$sql = "INSERT INTO `users`(`username`) VALUES (\'ciao\')";
 $username = $_POST['username'];$password = $_POST['password'];$email = $_POST['email'];$action = $_POST['action'];
if(isset($username) && isset($password) && isset($email)) {
  echo "<link href=\"css/custom_alert.css\" media=\"screen\" rel=\"stylesheet\" type=\"text/css\" />        <script src=\"//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js\"></script>        <script src=\"js/custom_alert.js\"></script>        <script type=text/javascript>_alert('LOL!','Sono isset!')</script>";            if(isset($action) && ($action=="Submit New Registration")) {

             $sql = mysql_query("SELECT `username` FROM `users`");
          while($u_namealreadyex = mysql_fetch_array($sql)) {                                        if(in_array($username, explode(",", $u_namealreadyex))) {
                               echo "<link href=\"css/custom_alert.css\" media=\"screen\" rel=\"stylesheet\" type=\"text/css\" />        <script src=\"//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js\"></script>        <script src=\"js/custom_alert.js\"></script>        <script type=text/javascript>_alert('Error!','Username already exists, choose another, try again','register.php')</script>";
                   }
               else if(! in_array($username, explode(",", $u_namealreadyex))) {
                                                   $salt = generateRandomImpossibleTosolveString("64");                $securepw = sha1(sha1($salt).md5($password));                $now = TIME_NOW;                        $query=mysql_query("INSERT INTO users (username, password, email) VALUES (".$username.", ".$securepw.", ".$email.")");
            while($done=mysql_fetch_array($query)) {
                   $user = array(                                          "username" => $username,                     "password" => $securepw,                     "email"    => $email,                     "memregdate" => $now,                     "lastactive" => $now,                     "lastvisit"  => $now         

                    );
            }
                  }       
          }

                         $sql=mysql_query("SELECT `email` FROM `users`");
       while($mailalreadyex = mysql_fetch_array($sql)) {
                  if(in_array($email, explode(",", $mailalreadyex))) {                         
                      echo "<link href=\"css/custom_alert.css\" media=\"screen\" rel=\"stylesheet\" type=\"text/css\" />        <script src=\"//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js\"></script>        <script src=\"js/custom_alert.js\"></script>        <script type=text/javascript>_alert('Error!','Email already exists, choose another, try again','register.php')</script>";  
                  }
                  else if(! in_array($email, explode(",", $mailalreadyex))) {
                                                   $salt = generateRandomImpossibleTosolveString("64");                $securepw = sha1(sha1($salt).md5($password));                $now = TIME_NOW;                        $query=mysql_query("INSERT INTO users (username, password, email) VALUES (".$username.", ".$securepw.", ".$email.")");
            while($done=mysql_fetch_array($query)) {
                   $user = array(                                          "username" => $username,                     "password" => $securepw,                     "email"    => $email,                     "memregdate" => $now,                     "lastactive" => $now,                     "lastvisit"  => $now         

                    );
            }
                  }
       }              

      }
}

?>

Restituisce questi errori:

Warning: explode() expects parameter 2 to be string, array given in /membri/hydrerscript/regverify.php on line 55

Warning: in_array() expects parameter 2 to be array, null given in /membri/hydrerscript/regverify.php on line 55

Warning: explode() expects parameter 2 to be string, array given in /membri/hydrerscript/regverify.php on line 64

Warning: in_array() expects parameter 2 to be array, null given in /membri/hydrerscript/regverify.php on line 64

Warning: sha1() expects at most 2 parameters, 3 given in /membri/hydrerscript/functions_custom.php on line 19

Warning: substr() expects at least 2 parameters, 1 given in /membri/hydrerscript/functions_custom.php on line 19

Notice: Use of undefined constant TIME_NOW - assumed 'TIME_NOW' in /membri/hydrerscript/regverify.php on line 69

Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in /membri/hydrerscript/regverify.php on line 73

Warning: explode() expects parameter 2 to be string, array given in /membri/hydrerscript/regverify.php on line 100

Warning: in_array() expects parameter 2 to be array, null given in /membri/hydrerscript/regverify.php on line 100

Warning: explode() expects parameter 2 to be string, array given in /membri/hydrerscript/regverify.php on line 110

Warning: in_array() expects parameter 2 to be array, null given in /membri/hydrerscript/regverify.php on line 110

Warning: sha1() expects at most 2 parameters, 3 given in /membri/hydrerscript/functions_custom.php on line 19

Warning: substr() expects at least 2 parameters, 1 given in /membri/hydrerscript/functions_custom.php on line 19

Notice: Use of undefined constant TIME_NOW - assumed 'TIME_NOW' in /membri/hydrerscript/regverify.php on line 115

Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in /membri/hydrerscript/regverify.php on line 119 

Come risolvere tutto?