Récupérer données formulaire dans une variable de session - How?

session_start ();

<?php
session_start();

if(!isset($_SESSION['zotikwa_iri']))
{
 header("location:./erreur.php"); // redirection
 exit; // arrêt du script
}

//La session est ouverte on peut afficher la page

?>
<?php require_once('Connections/pata.php'); ?>
<?php
if (!function_exists("GetSQLValueString")) {
function GetSQLValueString($theValue, $theType, $theDefinedValue = "", $theNotDefinedValue = "") 
{
  if (PHP_VERSION < 6) {
    $theValue = get_magic_quotes_gpc() ? stripslashes($theValue) : $theValue;
  }

  $theValue = function_exists("mysql_real_escape_string") ? mysql_real_escape_string($theValue) : mysql_escape_string($theValue);

  switch ($theType) {
    case "text":
      $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
      break;    
    case "long":
    case "int":
      $theValue = ($theValue != "") ? intval($theValue) : "NULL";
      break;
    case "double":
      $theValue = ($theValue != "") ? doubleval($theValue) : "NULL";
      break;
    case "date":
      $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
      break;
    case "defined":
      $theValue = ($theValue != "") ? $theDefinedValue : $theNotDefinedValue;
      break;
  }
  return $theValue;
}
}

$editFormAction = $_SERVER['PHP_SELF'];
if (isset($_SERVER['QUERY_STRING'])) {
  $editFormAction .= "?" . htmlentities($_SERVER['QUERY_STRING']);
}

if ((isset($_POST["MM_insert"])) && ($_POST["MM_insert"] == "env-form")) {
  $insertSQL = sprintf("INSERT INTO toka (toka_montant, toka_montant_apayer, toka_numero, toka_nom_exp, toka_prenom_exp, toka_tel_exp, toka_ville_exp, toka_msg, toka_piece_valide, toka_nom_ben, toka_pren_ben, toka_tel_ben, toka_type_piece_exp, toka_num_piece_exp, toka_question, toka_reponse, zotikwa_nom) VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)",
                       GetSQLValueString($_POST['toka_montant'], "text"),
                       GetSQLValueString($_POST['toka_montant_apayer'], "text"),
                       GetSQLValueString($_POST['toka_numero'], "text"),
                       GetSQLValueString($_POST['toka_nom_exp'], "text"),
                       GetSQLValueString($_POST['toka_prenom_exp'], "text"),
                       GetSQLValueString($_POST['toka_tel_exp'], "text"),
                       GetSQLValueString($_POST['toka_ville_exp'], "text"),
                       GetSQLValueString($_POST['toka_msg'], "text"),
                       GetSQLValueString($_POST['toka_piece_valide'], "text"),
                       GetSQLValueString($_POST['toka_nom_ben'], "text"),
                       GetSQLValueString($_POST['toka_pren_ben'], "text"),
                       GetSQLValueString($_POST['toka_tel_ben'], "text"),
                       GetSQLValueString($_POST['toka_type_piece_exp'], "text"),
                       GetSQLValueString($_POST['toka_num_piece_exp'], "text"),
                       GetSQLValueString($_POST['toka_question'], "text"),
                       GetSQLValueString($_POST['toka_reponse'], "text"),
                       GetSQLValueString($_POST['toko_nom_agent'], "text"));

  mysql_select_db($database_pata, $pata);
  $Result1 = mysql_query($insertSQL, $pata) or die(mysql_error());

  $insertGoTo = "imprimer.php";
  if (isset($_SERVER['QUERY_STRING'])) {
    $insertGoTo .= (strpos($insertGoTo, '?')) ? "&" : "?";
    $insertGoTo .= $_SERVER['QUERY_STRING'];
  }
  header(sprintf("Location: %s", $insertGoTo));
}

$colname_zoti = "-1";
if (isset($_SESSION['zotikwa_iri'])) {
  $colname_zoti = $_SESSION['zotikwa_iri'];
}
mysql_select_db($database_pata, $pata);
$query_zoti = sprintf("SELECT * FROM zotikwa WHERE zotikwa_iri = %s", GetSQLValueString($colname_zoti, "text"));
$zoti = mysql_query($query_zoti, $pata) or die(mysql_error());
$row_zoti = mysql_fetch_assoc($zoti);
$totalRows_zoti = mysql_num_rows($zoti);
?>

EDIT : Ajout des balises de code