Mine

 include('config.php');
 function getExtension($str) {         
 $i = strrpos($str,".");         
 if (!$i) { return ""; }         
 $l = strlen($str) - $i;         
 $ext = substr($str,$i+1,$l);       
 return $ext; 
 }
 if(isset($_POST['upload'])) {
 $error="0";
 $filename = stripslashes($_FILES['ufile']['name']);
 $extension = getExtension($filename);
 $extension = strtolower($extension);
 $extension_sql=mysql_query("SELECT * FROM extentions WHERE extention LIKE '".$extension."'", $connect);
 if(mysql_num_rows($extension_sql) < 1) { $error="1"; }
  $quota_sql=mysql_query("SELECT * FROM quota WHERE username LIKE '".$_SESSION['user']."'", $connect);
 $quota_data=mysql_fetch_assoc($quota_sql);
 $quota_avaialable=($quota_data['quota']-$quota_data['used'])/1024;
 if(filesize($_FILES['ufile']['name']) < $quota_available) { $error="2"; }
 if($error == "0") {
 $target="userdocs/".$_SESSION['user']."/";
 $result=copy($_FILES['ufile']['tmp_name'], $target_path);
 $error="3";
 }
 }