Description:
------------
Why in "static method" name of "parameter" can not be "$this" ?

Reproduce code:
---------------
<?php
header("Content-Type: text/plain; charset=koi8-r");

class Base
{
	public $x= 'x', $y= 'y';
	
	public static function fnTest($this)
	{
		echo __CLASS__,'::',__FUNCTION__,"()\t",get_class($this),"\n";
		list($this->x, $this->y)= array($this->y, $this->x);
		print_r($this);
	}
}

$o= new Base;
Base::fnTest($o);
?>

Expected result:
----------------
Base::fnTest()Base
Base Object
(
    [x] => y
    [y] => x
)

Actual result:
--------------
[Thu Feb 16 11:31:32 2006] [error] [client 192.168.0.250] PHP Fatal error:  Using $this when not in object context in D:\\dev\\Site\\test.htm on line 11