getting error : The upload path does not appear to be valid.

Code:

$this->load->helper(array('form', 'url'));



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

        

            $config['upload_path'] = './photos/';

        $config['allowed_types'] = 'gif|jpg|png';

        $config['max_size']    = '100';

        $config['max_width']  = '1024';

        $config['max_height']  = '768';



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



        if ( ! $this->upload->do_upload())

        {

            $error = array('error' => $this->upload->display_errors());



            $this->load->view('addvideo', $error);

        }

        else

        {

            $data = array('upload_data' => $this->upload->data());



            $this->load->view('addvideo', $data);

        }

Code:

&lt;html&gt;

&lt;head&gt;

&lt;title&gt;Upload Form&lt;/title&gt;

&lt;/head&gt;

&lt;body&gt;



&lt;?php echo $error;?&gt;



&lt;?php echo form_open_multipart('homemanagement/uploadVideo');?&gt;



&lt;input type="file" name="userfile" size="20" /&gt;



<br /><br />



&lt;input type="submit" value="upload" /&gt;



&lt;/form&gt;



&lt;/body&gt;

&lt;/html&gt;