Soldato
Try this.
PHP:
$x['foo'] = 'foo';
$x['foo']['bar'] = 'bar';
var_dump($x);
$x['foo'] = 'foo';
$x['foo']['bar'] = 'bar';
var_dump($x);
$x['foo'][] = 'bar';
$x['foo']['bar'] = 'bar';
var_dump($x);
$x['foo'] = 'foo';
$x['foo']['bar'] = 'bar';
$x['foo']['bar'] = 'bar';
$x = array('foo'=>'foo');
$x['foo'] = array('bar'=>'bar');