resize obrazku zadna chyba presto nefunguje

if(isset($_FILES['userfile'])) {

$num_query = $db->query("SELECT gall_id FROM gallery ORDER BY gall_id DESC LIMIT 1;");    //derniere numero
while($result=$db->fetch_assoc($num_query))
       
   {      
   $pl=$result['gall_id'];
   };  
  
  $pl=$pl+5;
   
  echo "$pl"; 
  
    if(!preg_match('/[.](gif|jpg|jpeg|png)$/',$_FILES['userfile']['name']))     //error pour type
    {
        $message="type de fichier non reconnu";  
        $image="";    
    }
    
    else if (preg_match('/[.](jpg)$/',$_FILES['userfile']['name'] )) {   
           //renome
         $image="img".$pl.".jpg";
         
    } else if (preg_match('/[.](gif)$/', $_FILES['userfile']['name'])) {  
         $image="img".$pl.".gif";  
         
    } else if (preg_match('/[.](png)$/', $_FILES['userfile']['name'])) {  
          $image="img".$pl.".png";    
    }
    else if (preg_match('/[.](jpeg)$/', $_FILES['userfile']['name'])) {  
          $image="img".$pl.".jpeg";    
    }
    

    
         
  $filename = $_FILES['userfile'].$image;  
  $source = $_FILES['userfile']['tmp_name'];            
  $target = $path_to_image_directory . $filename; 
  move_uploaded_file($source, $target);  
  
  $path_to_image_directory = '../images/';  
  $final_width_of_image = 100;  
  
     if(preg_match('/[.](jpg)$/', $filename)) {  
        $im = imagecreatefromjpeg($path_to_image_directory . $filename);  
    } else if (preg_match('/[.](gif)$/', $filename)) {  
        $im = imagecreatefromgif($path_to_image_directory . $filename);  
    } else if (preg_match('/[.](png)$/', $filename)) {  
        $im = imagecreatefrompng($path_to_image_directory . $filename);  
    }  
  
    $ox = imagesx($im);  
    $oy = imagesy($im);  
  
    $nx = $final_width_of_image;  
    $ny = floor($oy * ($final_width_of_image / $ox));  
  
    $nm = imagecreatetruecolor($nx, $ny);  
  
    imagecopyresized($nm, $im, 0,0,0,0,$nx,$ny,$ox,$oy);  
  
    if(!file_exists($path_to_image_directory)) {  
      if(!mkdir($path_to_image_directory)) {  
           die("There was a problem. Please try again!");  
      }  
       }  
    
  $message="SEND OK";  
  //
};