Fatal error: Call to a member function on a non-objec

<?php
require('db_connect.php');
$result = $conn->query ("SELECT name, category FROM animal");
if (DB::isError ($result))
die ("SELECT failed: " . $result->getMessage () . "n");
printf ("Result set contains %d rows and %d columnsn",
$result->numRows (), $result->numCols ());
while ($row = $result->fetchRow (DB_FETCHMODE_ASSOC))
printf ("%s, %sn", $row["name"], $row["category"]);
$result->free ();

$db_object->disconnect();
?>
i am trying to return a value from a selected field actually fields and testing them with php4 and mysql and i just started using pear.....can someone help me and point me in the right direction?

Your using PEAR DB right?

$result =& $conn->query ("SELECT name, category FROM animal");

You forgot the ampersand for the return value. You were only getting a copy of the result set - not the actual result set.