Facing the following error

> 
> Error: Notice: Undefined index: id in /Applications/XAMPP/xamppfiles/htdocs/mks/opencart-1.5.6.1/upload/admin/controller/catalog/vendhqbridge.php on line 120
> 
> 
> 

Relevant code:

```
//check for existing 'VendHQ_id' on  DB's product table

function checkVendHQid($flagChk)
{
$rs = $this->db->query("SELECT vendhq_id as id FROM ".DB_PREFIX."vendhq_product WHERE vendhq_id = '".$flagChk."'");

     $rowRsl=-1;
     if($rs===null)
    {
        $rowRsl = -1;
    }
    else
    {
       if($rs->row["id"] == $flagChk  )
       {
           $rowRsl = 1;
       }
    }

    return $rowRsl;
 }

```