multiple image upload in single input

Question

I am trying to add multiple image upload in a codeigniter. What i have achieved so far that i can save one image in my database.But i want to add multiple image in single input.How can i do that?? Thanx in advance :) This is my controller:

public function customer_insert() {
        $oidVal = implode(",", $this->input->post('multiselect'));
        $config['upload_path'] = 'images/';
        $config['allowed_types'] = 'gif|jpg|png|tif|docx|doc|pdf';
        $config['max_size'] = '100000';
        $config['max_width'] = '30000';
        $config['max_height'] = '30000';
        $this->load->library('upload', $config);
        $this->upload->initialize($config);

        if ($this->upload->do_upload()) {
            $fata = array('upload_data' => $this->upload->data());
            $path = 'images/' . $fata['upload_data']['orig_name'];
        }
        $data = array(
              'prof_image' => $path  
        );
        $this->db->insert('customer', $data);
    }

My view file:

<?php echo form_open_multipart('main/customer_insert');?>
<?php
$picture=array(
    'type'=>'file',
    'class'=>'form-control',
    'name'=>"userfile",
);

$submit=array(
    'name'=>'submit',
    'type'=>'submit',
    'class'=>'btn btn-primary btn-o pull-right next-step btn-wide',
    'value'=>'Save',
)
?>

  <div class="form-group">
                                            <label class="control-label">
                    Cutomer Image <span class="symbol required"></span>
                                            </label>
                                            <?php echo form_upload($picture);?>
                                        </div>