I can't Upload File

[eluser]harly[/eluser]
I save code in my server but mycode problem in server. but i'm running in my pc ( localhost) no problem.
please help me.


Error:
Fatal error: Call to a member function do_upload() on a non-object in


mycode:
function upload(){
$config['upload_path'] = 'upload/';
$config['allowed_types'] = 'pdf|jpeg|jpg';
$config['file_name'] = $data;
$config['max_size'] = '1000000';

$this->load->library('upload', $config);
if(!$this->upload->do_upload()){
echo "warnin";
}else {
echo "succes";
}
}