Codeigniter Image Upload

public function save_admin(){
		$data =	array();
		$data['admin_image'] = $this->input->post('admin_image',true);
		$sdata = array();
		$error = "";
		$config['upload_path']          = 'uploads/';
                $config['allowed_types']        = 'gif|jpg|png';
                $config['max_size']             = 100000;
                $config['max_width']            = 1024;
                $config['max_height']           = 768;

                $this->load->library('upload', $config);

                if ( ! $this->upload->do_upload('admin_image'))
                {
                        $error = $this->upload->display_errors();                        
                }
                else
                {
                        $sdata = $this->upload->data();

                        $data['admin_image'] = $sdata['file_name'];
                }
        
		$this->db->INSERT('admin',$data);
	}