Specify different error level reporting:

<?php
// Turn off error reporting
error_reporting(0);

// Report runtime errors
error_reporting(E_ERROR | E_WARNING | E_PARSE);

// Report all errors
error_reporting(E_ALL);

// Same as error_reporting(E_ALL);
ini_set("error_reporting", E_ALL);

// Report all errors except E_NOTICE
error_reporting(E_ALL & ~E_NOTICE);
?>