Simple object problem

[Electric_Studio]

I am new to objects, and cannot understand the following:

echo $this->currentcontent; // echoes "test"
$output->content=$this->currentcontent;
echo $output->content; // echoes ""

Why is it echoing nothing?

[laserlight]

Works for me:

<?php
class X
{
    public $content;
}

class Y
{
    private $currentcontent = 'test';

function foo()
{
    $output = new X();
    echo $this->currentcontent;
    $output->content=$this->currentcontent;
    echo $output->content;
}
}

$y = new Y();
$y->foo();
?>

I get the output "testtest".

In other words, provide the smallest and simplest (runnable) script that demonstrates the problem.