Search result and pagination class

[eluser]djalilk[/eluser]
This is the url I get when I use urldecode: welcome/search/banque+d'/16/1

And the same error is returned :

The URI you submitted has disallowed characters.


Below the search method I'm using

Code:

function search($keyword = null , $city= null ,$offset = null) {





if( $this->input->post('item') ) {

     $keyword = $this->input->post('item');
     $city = $this->input->post('city_id');


}

$config['base_url'] = site_url().'/welcome/search/'.urlencode($keyword).'/'.$city;
$config['total_rows'] = $this->Place->totalProductBySearch($keyword, $city);
$config['per_page'] = '1';





$this->pagination->initialize($config);
$data['result'] = $this->Place->find(urldecode($keyword), $city , $config['per_page'], $offset);
echo  $this->pagination->create_links();


$data['main'] = 'result';
$data['citys'] = $this->city->getcitysDropDown();
$this->load->vars($data);
$this->load->view('template',$data);

}