Logging user access with IP..?

Question

I want oto add some user logging for my site and since it requires authentication I believe most of the heavy lifting has already been completed. I'm hoping someone can give me some direction as to how to incorporate the pieces I need into what I have already existing.
Currently I believe the following is the php for granting access on my site:
<?php
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;
$MM_restrictGoTo = "../logon.php";
if (!((isset($_SESSION['MM_Username'])) && (isAuthorized("",$MM_authorizedUsers, $_SESSION['MM_Username'], $_SESSION['MM_UserGroup'])))) {  
  $MM_qsChar = "?";
  $MM_referrer = $_SERVER['PHP_SELF'];
  if (strpos($MM_restrictGoTo, "?")) $MM_qsChar = "&";
  if (isset($QUERY_STRING) && strlen($QUERY_STRING) > 0)
  $MM_referrer .= "?" . $QUERY_STRING;
  $MM_restrictGoTo = $MM_restrictGoTo. $MM_qsChar . "accesscheck=" . urlencode($MM_referrer);
  header("Location: ". $MM_restrictGoTo);
  exit;
?>
I believe some of the pieces I'm missing are the IP address for the user and the sql needed for the INSERT into mySQL which I believe are as follows:
$ip_address = $_SERVER["REMOTE_ADDR"];
       $sql = "INSERT INTO  user_tracking
              (username, ip_address)
              VALUES ('MM_Username', '$ip_address')";
mysql_query($sql, $maxdbconn) or die(mysql_error());       'Is this the command for executing the SQL???
My problem is I'm still green and don't understand the php routine well enough to be able to plug in these pieces and whether I'm missing something else so I'm hoping someone can help shed some light.
Thanks.
A JM,

Answer 1

I found the original page and again I realize that I was missing some original code, I realize it makes it tough to follow - my appologies. I tested this source below and all is back to normal.
So, back to trying to add the user to the tracking DB.
I think the pieces I'm missing are as follows- not sure though...????
    //SQL string for user logged in
    $insertSQL = "INSERT INTO user_tracking (username, ip_address) VALUES ('maxadmin', '192.168.1.100')";
    mysql_select_db($database_maxdbconn, $maxdbconn);
    $Result1 = mysql_query($insertSQL, $maxdbconn) or die(mysql_error());
However, when I add the lines before ( header("Location: " . $MM_redirectLoginSuccess ); )  I get an error message in Dreamweaver, "The Server Behavior panel cannot determine whether "Log In User" or "Log In User" is applied to your page. Please select Edit Server Behaviors and change one of the two behaviors to ensure that each is uniquely identifiable."
A JM,
<?php require_once('Connections/maxdbconn.php'); ?>
<?php
if (!function_exists("GetSQLValueString")) {
function GetSQLValueString($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 $theValue;
?>
<?php
// *** Validate request to login to this site.
if (!isset($_SESSION)) {
  session_start();
$loginFormAction = $_SERVER['PHP_SELF'];
if (isset($_GET['accesscheck'])) {
  $_SESSION['PrevUrl'] = $_GET['accesscheck'];
if (isset($_POST['username'])) {
  $loginUsername=$_POST['username'];
  $password=$_POST['password'];
  $MM_fldUserAuthorization = "";
  $MM_redirectLoginSuccess = "dbpages/claimroot.php";
  $MM_redirectLoginFailed = "failedlogin.html";
  $MM_redirecttoReferrer = false;
  mysql_select_db($database_maxdbconn, $maxdbconn);
  $LoginRS__query=sprintf("SELECT username, password FROM users WHERE username=%s AND password=%s",
    GetSQLValueString($loginUsername, "text"), GetSQLValueString($password, "text"));
  $LoginRS = mysql_query($LoginRS__query, $maxdbconn) or die(mysql_error());
  $loginFoundUser = mysql_num_rows($LoginRS);
  if ($loginFoundUser) {
     $loginStrGroup = "";
    //declare two session variables and assign them
    $_SESSION['MM_Username'] = $loginUsername;
    $_SESSION['MM_UserGroup'] = $loginStrGroup;         
    if (isset($_SESSION['PrevUrl']) && false) {
      $MM_redirectLoginSuccess = $_SESSION['PrevUrl'];   
    header("Location: " . $MM_redirectLoginSuccess );
  else {
    header("Location: ". $MM_redirectLoginFailed );
?>