simple file uploading function in php with mysql_ database

function file_upload($f, $folder) {
  extract($f);
  echo("<pre>");
  print_r($f);
  echo("</pre>");
  //echo($f["photo"]["type"]);

  $name = $f["photo"]["name"];
  $tmp_name = $f["photo"]["tmp_name"];
  $size = $f["photo"]["size"];
  $type = $f["photo"]["type"];

  //$extension=array("image/png","image/jpg","image/gif");
  if ($type == "image/png" || $type == "image/jpg" || $type == "image/gif" || $type == "image/jpeg") {
   $ext = end(explode(".", $name));
   ;
   $encname = substr(md5($name), 0, 8) . "." . $ext;
   if ($folder == "") {
    $folder = date("d_m_y");
    $folder = "gallery/" . $folder;
    if (!file_exists($folder)) {
     mkdir($folder);
    }
   }
   
   $path = $folder . "/" . $encname;
   
   $a = move_uploaded_file($tmp_name, $folder . "/" . $encname);
   if ($a) {
    $ginert = $this->insertquery("insert into gallery (gid,name,encname,size,path)  values('','$name','$encname','$size','$path') ", "file_upload");
    if ($ginert) {
     return mysql_insert_id();
    }
   } else {
    echo("error");
   }
  } else {
   echo("unknown file type");
  }
 }
 
 
 /*
 just pass global array of $_FILES or your cutomize array with temp file 
 $f=arrray();
 $f=$_FILES;  //(file name should photo means $_FILES["photo"]["name"] );
 $folder="user_upload";
 
 
 
 
 file_upload($f, $folder)
 
 
 
 */