Converting to Pear

Hi, I am in the process of learning Pear. I though that converting an old script would be the way to go. Everything has been going well until now when i get the error, Notice: Undefined index: for tutorial, owner, and address in the following code. Where am I screwing up? while ($row = $res->fetchRow()){

	    	$tutorial = $row["tutorial"];
	    	$owner = $row["owner"];
	        $address = $row["address"];

TIA Gary