hello
i followed the instructions for creating new joomsef extension for my own component but iam failed .
Please check the code below that i used for my extension
<?php
/**
 * SEF module for Joomla!
 *
 * @author      $Author: michal $
 * @copyright   ARTIO s.r.o., http://www.artio.cz
 * @package     JoomSEF
 * @version     $Name$, ($Revision: 4994 $, $Date: 2005-11-03 20:50:05 +0100 (??t, 03 XI 2005) $)
 */
 
// Security check to ensure this file is being included by a parent file.
if (!defined('_VALID_MOS')) die('Direct Access to this location is not allowed.');
 
class sefext_com_testvideo extends sef_joomsef
 
{
//print_r($_REQUEST);
//exit;
 function Create($string, &$vars) {
        global $sefConfig, $debug, $debug_string;
 
        extract($vars); $title = array();
 
switch ($task) {
  case 'showclasses':
      if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-0';}else {  
			 $title[] =  'myclass-/'.$classid.'-0';}
			 break;
  case 'showcomments':
			if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-1';}else {  
			 $title[] =  'myclass-/'.$classid.'-1';}
			 break;
  case 'showvocabularies':
			if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-2';}else {  
			 $title[] =  'myclass-/'.$classid.'-2';}
			 break;
  case 'showdialogues':
			if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-3';}else {  
			 $title[] =  'myclass-/'.$classid.'-3';}
			 break;
  case 'showphrases':
	 		if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-4';}else {  
			 $title[] =  'myclass-/'.$classid.'-4';}
			 break;
  case 'showwiki':
	 		if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-5';}else {  
			 $title[] =  'myclass-/'.$classid.'-5';}
			 break;
  case 'showcomprehensions':
	 		if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-6';}else {  
			 $title[] =  'myclass-/'.$classid.'-6';}
			 break;
  case 'showpictures':
	 		if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-7';}else {  
			 $title[] =  'myclass-/'.$classid.'-7';}
			 break;
  case 'showhanzi':
	 		if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-8';}else {  
			 $title[] =  'myclass-/'.$classid.'-8';}
			 break;
  case 'showtranslate':
	 		if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-9';}else {  
			 $title[] =  'myclass-/'.$classid.'-9';}
			 break;
  case 'showlistening':
	 	if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-10';}else {  
			 $title[] =  'myclass-/'.$classid.'-10';}
			 break;
  case 'showmatching':
	 		if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-11';}else {  
			 $title[] =  'myclass-/'.$classid.'-11';}
			 break;
  case 'showfillin':
	 		if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-12';}else {  
			 $title[] =  'myclass-/'.$classid.'-12';}
			 break;
  case 'showgrammar':
	 		if(($row->classid)%2==0){
  $title[] =  'myclass-/'.$classid.'-13';}else {  
			 $title[] =  'myclass/'.$classid.'-13';}
			 break; 
}
 
    // $title[] = $sefConfig->suffix;
 
$nonSefVars = array();
        if (count($title) > 0) {
if (isset($classid))       $nonSefVars['classid'] = $classid;
		$string = sef_joomsef::sefGetLocation($string, $title, @$task, null, null, null);}
 
 
//$string = sef_joomsef::sefGetLocation($string, $title, @$task, @$limit, @$limitstart, @$lang);
 
        if ($debug) { $GLOBALS['JOOMSEF_DEBUG']['CLASS_SEF_JOOMSEF'][$debug_string]['STRING'] = $string; }
 
 
 
 
        return $string;
    }
}
?>