thumbnail problem...

[eyeofthestorm]

here is my code. it does exactly what i want it to do...upload an image and then create a thumbnail. only problem is...when i create the thumbnail. its not so much as a thumbnail as it is a small black picture. because the entire thing is just black. not a smaller version of the picture. any help please?

if ($_FILES['file']['type'] == "image/gif" or $_FILES['file']['type'] == 'image/jpeg' or $_FILES['file']['type'] == 'image/pjpeg'){ 
    $target_path = './data/images/uploads/'; 
    $thumb_path = $target_path."thumbs/"; 
    $target_path = $target_path . basename( $_FILES['file']['name']); 
    if(move_uploaded_file($_FILES['file']['tmp_name'], $target_path)) { 
        echo "The file ". basename( $_FILES['file']['name']). " has been uploaded<br>"; 
} else{ 
     die("There was an error uploading the file, please try again!"); 
} 
} else { 
    die("File must be an image<br>"); 
} 
        createthumb($target_path,$thumb_path.basename( $_FILES['file']['name']),59,59); 

the createthumb function:

function createthumb($name,$filename,$new_w,$new_h)
{
    $size = getimagesize($name);
 $system=explode(".",$name);
 if (preg_match("/jpg|jpeg/",$system[1])){$src_img=imagecreatefromjpeg($name);}
 if (preg_match("/png/",$system[1])){$src_img=imagecreatefrompng($name);}
 $old_x=$size[0];
 $old_y=$size[1];
 if ($old_x > $old_y) 
 {
  $thumb_w=$new_w;
  $thumb_h=$old_y*($new_h/$old_x);
 }
 if ($old_x < $old_y) 
 {
  $thumb_w=$old_x*($new_w/$old_y);
  $thumb_h=$new_h;
 }
 if ($old_x == $old_y) 
 {
  $thumb_w=$new_w;
  $thumb_h=$new_h;
 }
 $dst_img = imagecreatetruecolor($thumb_w,$thumb_h);
 imagecopyresampled($dst_img,$src_img,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y); 
 if (preg_match("/png/",$system[1]))
 {
  imagepng($dst_img,$filename); 
 } else {
  imagejpeg($dst_img,$filename); 
 }
 imagedestroy($dst_img); 
 imagedestroy($src_img); 
}