PHP probleem

<?php 
    session_start(); 
     
    // ingelogd check 
    if(!$_SESSION['id'] || $_SESSION['ip'] !== md5($_SERVER['REMOTE_ADDR'])) 
    { 
        header("location: login.php"); 
        die(); 
    } 
    $id = $_SESSION['id'] ; 
     
    // page name 
    $page = "dashboard"; 
     
    // load system files 
    require_once('inc/config.php'); 
    require_once('inc/functions.php'); 
     
    // load page script 
     
     
    // load html 
    require_once('inc/inc.header.php'); 
    require_once('inc/inc.nav.php'); 
?> 


    <div id="content"> 
     
         <? 
  if(isset($_POST['bewerk'])) { 
         
  
                mysql_query("UPDATE match_makelaars SET makelaar_kantoor = '" . mysql_real_escape_string($_POST['kantoor']) . "', makelaar_contactpersoon = '" . mysql_real_escape_string($_POST['contactpersoon']) . "', makelaar_adres = '" . mysql_real_escape_string($_POST['adres']) . "', makelaar_postcode = '" . mysql_real_escape_string($_POST['postcode']) . "', makelaar_telefoon = '" . mysql_real_escape_string($_POST['telefoon']) . "', makelaar_mail = '" . mysql_real_escape_string($_POST['mail']) . "' WHERE eigenpand_id = '" . mysql_real_escape_string($_GET['id']) . "'"); 
  
                echo "<b>Het pand is succesvol bewerkt</b>"; 
 } else { 
         
         $result = mysql_query("SELECT * FROM match_makelaars WHERE makelaar_id = '" . mysql_real_escape_string($_GET['id']) . "'"); 
  
  echo "<form method='POST'>"; 
        while($row = mysql_fetch_assoc($result)) {     
        echo "     
                <div id='left'> 
                <label>Makelaarskantoor:</label> 
                <input type='text' class='text' name='kantoor' value='' . $row['makelaar_kantoor'] . '' /> 
                 
                <label>Contactpersoon</label> 
                <input type='text' class='text' name='contactpersoon' value='' . $row['makelaar_contactpersoon'] . '' /> 
                 
                <label>Adres:</label> 
                <input type='text' class='text' name='adres' value='' . $row['makelaar_adres'] . '' /> 
                 
                 
                 
                    <div id='right'> 
                     
                    <label>Postcode:</label> 
                <input type='text' class='text' name='postcode' value='' . $row['makelaar_postcode'] . '' /> 
                </div> 
                 
                <label>Telefoonnummer:</label> 
                <input type='text' class='text' name='telefoon' value=' ' . $row['makelaar_telefoon'] . '' /> 
                 
                <label>E-mailadres:</label> 
                <input type='text' class='text' name='mail' value='' . $row['makelaar_mail'] . '' /> 
                </div> 
             
             
                 
                <div class="padding-right"> 
                    <input type='submit' class='submit' name='verstuur' value='Verstuur' /> 
                    <span class='clear'></span> 
                </div> 
         
                          </form>
						  
						  
						  "; 
        } 
 } 
    ?> 


         
    </div> 
     
<?php 
    require_once('inc/inc.footer.php'); 
?>

echo "     
                <div id='left'> 
                <label>Makelaarskantoor:</label> 
                <input type='text' class='text' name='kantoor' value='" . $row['makelaar_kantoor'] . "' /> 
                 
                <label>Contactpersoon</label> 
                <input type='text' class='text' name='contactpersoon' value='" . $row['makelaar_contactpersoon'] . "' /> 
                 
                <label>Adres:</label> 
                <input type='text' class='text' name='adres' value='" . $row['makelaar_adres'] . "' /> 
                 
                 
                 
                    <div id='right'> 
                     
                    <label>Postcode:</label> 
                <input type='text' class='text' name='postcode' value='" . $row['makelaar_postcode'] . "' /> 
                </div> 
                 
                <label>Telefoonnummer:</label> 
                <input type='text' class='text' name='telefoon' value='" . $row['makelaar_telefoon'] . "' /> 
                 
                <label>E-mailadres:</label> 
                <input type='text' class='text' name='mail' value='" . $row['makelaar_mail'] . "' /> 
                </div> 
             
             
                 
                <div class='padding-right'> 
                    <input type='submit' class='submit' name='verstuur' value='Verstuur' /> 
                    <span class='clear'></span> 
                </div> 
         
                          </form>
                          
                          
                          ";