magento rewrite url

"designeruser" ia a custom module rewrite Url
http://localhost/magentotest/designeruser/index/index/id/1/ to
http://localhost/magentotest/designeruser/id/1/



$store_id=1;

$request_path = 'designeruser/id/2/' ;
$target_path='designeruser/index/index/id/2';
$rewriteModel = Mage::getModel('core/url_rewrite');
$id_path ='designeruser/index/index/id/2';
$rewriteModel->setData('request_path', $request_path);
$rewriteModel->setData('target_path', $target_path);
$rewriteModel->setData('id_path',$id_path);
$rewriteModel->setData('store_id', $store_id);
$rewriteModel->setData('is_system', 0);
$rewriteModel->save();




$store_id=1;
$request_path = 'designeruser/id/2/' ;
$target_path='designeruser/index/index/id/2';
$oUrlRewriteCollection = Mage::getModel('core/url_rewrite')->getCollection()->addFieldToFilter('target_path', $target_path); //check rewrite url exit or not
if(count($oUrlRewriteCollection)==0){
    echo "target path does exist";
$rewriteModel = Mage::getModel('core/url_rewrite');
$id_path ='designeruser/index/index/id/2';
$rewriteModel->setData('request_path', $request_path);
$rewriteModel->setData('target_path', $target_path);
$rewriteModel->setData('id_path',$id_path);
// $rewriteModel->setOptions('RP');
$rewriteModel->setData('store_id', $store_id);
$rewriteModel->setData('is_system', 0);
$rewriteModel->save();
}