<?php 

class foo {
	function __construct($theArguments) {
		echo 'i need $theArguments to work';
	}
	function barfoo($text) {
		echo $text;
	}
}

class bar extends foo {
	function foobar() {
		// some code
		$this->barfoo('bla');
	}
}

$class = new bar;
$class->foobar();
// err: Debug Warning: phpfile.php line 3 - Missing argument 1 for foo::__construct()

?>