Class function "Undefined Property" error

[Marty Meyers]

TIA for your help!
Using PHP 4.3.9 doing some code cleanup on an existing site.
I have reduced the problem to:
This File is marty.php:
<?
class Refs {
function scriptDir() {
echo "Refs are Here\n";
}
}

$ref = new Refs;
$ref->scriptDir;

?>

When executed from command line I get the following:
PHP Notice: Undefined property: scriptDir in /............./marty.php on
line 10

I suspect the problem is an improper setting in php.ini. (SafeMode = Off)

Thanks
Marty