数组返回，枚举或其他解决方案？

I'm having trouble identifying each row of this array ... would it be possible to enumerate or otherwise be able to pull a specific array field?

My code is:

<?php

/*
    Generic function to fetch all input tags (name and value) on a page
Useful when writing automatic login bots/scrapers
*/
function get_input_tags($html)
{
    $post_data = array();

    // a new dom object
    $dom = new DomDocument; 

    //load the html into the object
    $dom->loadHTML($html); 
    //discard white space
    $dom->preserveWhiteSpace = false; 

    //all input tags as a list
    $input_tags = $dom->getElementsByTagName('input'); 

    //get all rows from the table
    for ($i = 0; $i < $input_tags->length; $i++) 
    {
        if( is_object($input_tags->item($i)) )
        {
            $name = $value = '';
            $name_o = $input_tags->item($i)->attributes->getNamedItem('name');
            if(is_object($name_o))
            {
                $name = $name_o->value;

                $value_o = $input_tags->item($i)->attributes->getNamedItem('value');
                if(is_object($value_o))
                {
                    $value = $input_tags->item($i)->attributes->getNamedItem('value')->value;
                }

                $post_data[$name] = $value;
            }
        }
    }

    return $post_data;
}

/*
    Usage
*/

error_reporting(~E_WARNING);
$html = file_get_contents("https://secure.donman.net.au/client/ozchild/Donate.aspx");

echo "<pre>";
print_r(get_input_tags($html));
echo "</pre>";

?>

Generate the result

[radInMemDiscloseAmount] => No
[txtInMemOfAddress] => 
[txtInMemOfSuburb] => 
[txtInMemOfState] => 
[txtInMemOfPostCode] => 
[txtInHonorOfName] => 
[txtInHonorOfAddress] => 
[txtInHonorOfSuburb] => 
[txtInHonorOfState] => 
[txtInHonorOfPostCode] => 
[HonorEventType] => gf_other_choice
[HonorEventTypeOtherText] => Other

how can I have something like this?

    [0][radInMemDiscloseAmount] => No
    [1][txtInMemOfAddress] => 
    [2][txtInMemOfSuburb] => 
    [3][txtInMemOfState] => 
    [4][txtInMemOfPostCode] => 
    [5][txtInHonorOfName] => 
    [6][txtInHonorOfAddress] => 
    [7][txtInHonorOfSuburb] => 
    [8][txtInHonorOfState] => 
    [9][txtInHonorOfPostCode] => 
    [10][HonorEventType] => gf_other_choice
    [11][HonorEventTypeOtherText] => Other

how can I have something like this? or some way to identify array rows? I'm having trouble identifying each row of this array ... would it be possible to enumerate or otherwise be able to pull a specific array field?