Connecting to 2 databases in a snippet

function GetCartId()
	{
		// This function will generate an encrypted string and
  	// will set it as a cookie using set_cookie. This will
		// also be used as the cookieId field in the cart table
		if(isset($_COOKIE["id"]))
		{
			return $_COOKIE["id"];
		}
		else
		{
			// There is no cookie set. We will set the cookie
			// and return the value of the users session ID			
			error_reporting(0);
                        session_start();
			setcookie("id", session_id(), time() + ((3600 * 24) * 30));
			return session_id();
		}
	}

if (empty($_GET["action"]))
  {}
else
{
$action = $_GET["action"];
$item_id = $_GET["item_id"]; 
switch($action)
	{
	case "add_item":
             { 
		    $mydb= new DBAPI();
        $mydb->connect('localhost','db', 'user','pwd');
    $cookie = GetCartId();
		$table = 'cart';
		$where = 'cookie="'.$cookie.'"';
		$rs = $mydb->select("*", $table, $where, '', '');
		if ($mydb->getRecordCount($rs) > 10)
		    {$msg ="The shopping cart is full. You cannot add more than 10 items";}
	  else
	       {...
               $msg = "The item has ben added to your cart";
               ...}
        $mydb->disconnect();
        
        $modx->setPlaceholder('msg', $msg);  
             } 
        }
}