Attach User Id to inserted records

thanks so much.. i know exactly what you MEAN i need to do.. but have no clue how to do it    right now... the insert code from my form looks like the following:

if ((isset($_POST["MM_insert"])) && ($_POST["MM_insert"] == "form3")) {

  $insertSQL = sprintf("INSERT INTO sponsors (studentid, schoolid, sponsorname, sponsor_address1, sponsor_address2, sponsor_city, sponsor_state, sponsor_zip, status, `level`, signed_contract, total_due, pymt_rcvd, prize_rcvd, prize_to_sgf) VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)",

                       GetSQLValueString($_POST['studentid'], "int"),

                       GetSQLValueString($_POST['schoolid'], "int"),

                       GetSQLValueString($_POST['sponsorname'], "text"),

                       GetSQLValueString($_POST['sponsor_address1'], "text"),

                       GetSQLValueString($_POST['sponsor_address2'], "text"),

                       GetSQLValueString($_POST['sponsor_city'], "text"),

                       GetSQLValueString($_POST['sponsor_state'], "text"),

                       GetSQLValueString($_POST['sponsor_zip'], "int"),

                       GetSQLValueString($_POST['status'], "text"),

                       GetSQLValueString($_POST['level'], "text"),

                       GetSQLValueString($_POST['signed_contract'], "date"),

                       GetSQLValueString($_POST['total_due'], "double"),

                       GetSQLValueString($_POST['pymt_rcvd'], "date"),

                       GetSQLValueString($_POST['prize_rcvd'], "date"),

                       GetSQLValueString($_POST['prize_to_sgf'], "date"));

I have studentid and schoolid hidden so students can't populate them... i want them populated by the session variable..   right now my session variable for this page looks like this:

if (!isset($_SESSION)) {

  session_start();

}

$MM_authorizedUsers = "";

$MM_donotCheckaccess = "true";

// *** Restrict Access To Page: Grant or deny access to this page

function isAuthorized($strUsers, $strGroups, $UserName, $UserGroup) {

  // For security, start by assuming the visitor is NOT authorized.

  $isValid = False;

  // When a visitor has logged into this site, the Session variable MM_Username set equal to their username.

  // Therefore, we know that a user is NOT logged in if that Session variable is blank.

  if (!empty($UserName)) {

    // Besides being logged in, you may restrict access to only certain users based on an ID established when they login.

    // Parse the strings into arrays.

    $arrUsers = Explode(",", $strUsers);

    $arrGroups = Explode(",", $strGroups);

    if (in_array($UserName, $arrUsers)) {

      $isValid = true;

    }

    // Or, you may restrict access to only certain users based on their username.

    if (in_array($UserGroup, $arrGroups)) {

      $isValid = true;

    }

    if (($strUsers == "") && true) {

      $isValid = true;

    }

  }

  return $isValid;

}

$MM_restrictGoTo = "index.php";

if (!((isset($_SESSION['MM_Username'])) && (isAuthorized("",$MM_authorizedUsers, $_SESSION['MM_Username'], $_SESSION['MM_UserGroup'])))) {  

  $MM_qsChar = "?";

  $MM_referrer = $_SERVER['PHP_SELF'];

  if (strpos($MM_restrictGoTo, "?")) $MM_qsChar = "&";

  if (isset($_SERVER['QUERY_STRING']) && strlen($_SERVER['QUERY_STRING']) > 0)

  $MM_referrer .= "?" . $_SERVER['QUERY_STRING'];

  $MM_restrictGoTo = $MM_restrictGoTo. $MM_qsChar . "accesscheck=" . urlencode($MM_referrer);

  header("Location: ". $MM_restrictGoTo);

  exit;

}

?>

given all of this information... are you able to help me with inserting the correct information/syntax here so that i can capture from my users table the studentid and schoolid to be inserted into the sponsors table?