How to upload image in CodeIgniter?

Question

In view

 <?php echo form_open_multipart('welcome/do_upload');?>
 <input type="file" name="userfile" size="20" />

In controler

function do_upload()
{
    $config['upload_path'] = './uploads/';
    $config['allowed_types'] = 'gif|jpg|png';
    $config['max_size'] = '100';
    $config['max_width']  = '1024';
    $config['max_height']  = '768';
    $config['overwrite'] = TRUE;
    $config['encrypt_name'] = FALSE;
    $config['remove_spaces'] = TRUE;
    if ( ! is_dir($config['upload_path']) ) die("THE UPLOAD DIRECTORY DOES NOT EXIST");
    $this->load->library('upload', $config);
    if ( ! $this->upload->do_upload('userfile')) {
        echo 'error';
    } else {

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

And I call this function like this

 $this->data['data'] = $this->do_upload();

and view this image:

<ul>
<?php foreach ($data['upload_data'] as $item => $value):?>
<li><?php echo $item;?>: <?php echo $value;?></li>
<?php endforeach; ?>
</ul>

I don't know what's the error.

Answer 1

$image_folder = APPPATH . "../images/owner_profile/" . $_POST ['mob_no'] [0] . $na;
            if (isset ( $_FILES ['image'] ) && $_FILES ['image'] ['error'] == 0) {
                list ( $a, $b ) = explode ( '.', $_FILES ['image'] ['name'] );
                $b = end ( explode ( '.', $_FILES ['image'] ['name'] ) );
                $up = move_uploaded_file ( $_FILES ['image'] ['tmp_name'], $image_folder . "." . $b );
                $path = ($_POST ['mob_no'] [0] . $na . "." . $b);