This does not work as expected.

<?php
class someclass
{
    var $query_string;
    function someclass($a_query_string)
    {
        $this->query_string = $a_query_string;
        parse_str($this->query_string);
    }
    function output()
    {
        echo $this->action;
    }
}

$a_class = new someclass("action=go");
$a_class->output();
?>

Use this instead.

<?php
class someclass
{
    var $arr;
    function someclass($a_query_string)
    {
        parse_str($a_query_string, $this->arr);
    }
    function output()
    {
        echo $this->arr['action'];
    }
}

$a_class = new someclass("action=go");
$a_class->output();
?>