insert a data from check box in to database with selected fields in codeigniter

i the check box list from another database table into my form and now i have to add database in my registration table with selected check box values. on submitting form the database only show the last check box values's id.

I call plan task form different table. i want to show the checked task in my inserting data.

this is the insert Model.

public function vedding_plan_add()
{
    $data = array(
        'vedd_title' => $this->input->post('vedd_title'),
        'vedd_price' => $this->input->post('vedd_price'),
        'vedd_desc'     => $this->input->post('vedd_desc'),
        'vedd_task_id' => $this->input->post('vedd_task_id')
    );

    $this->db->insert('vedd_plan',$data);
    return;
}

this is my controller

public function plan_add()
    {
        $this->m->vedding_plan_add('$data');
        $this->index();
    }

and this is the view

<?php  echo form_open('Plan_model/plan_add'); ?>        
    <p>
    <lable for="vedd_title">Plan Title:</lable>
    <input type="text" name="vedd_title" id="vedd_title" />
    </p>
    <p>
    <lable for="vedd_price">Plan Price:</lable>
    <input type="text" name="vedd_price" id="vedd_price" />
    </p>
    <p>
    <lable for="vedd_desc">Plan Description:</lable>
    <input type="text" name="vedd_desc" id="vedd_desc" />
    </p>
    <p>
    <lable>Select Task:</lable>
    <?php if(isset($records_task)) : foreach ($records_task as $row) { ?>

    <input type="checkbox" name="vedd_task_id" value="<?=$row->vedd_task_id?>"><?=$row->task_name?><br>
    <?php } ?>
        <?php else: ?>
        <?php endif; ?>
    </p>    
    <input type="submit" value="submit" />
<?php  echo form_close(); ?>