child.name.substring is not a function

[eluser]Iverson[/eluser]
I have a button with

Code:

'onclick' => 'xajax_add_posts(xajax.getFormValues(\'add-post-biz\'));',

The function is simply

Code:

function add_posts($form_data)
{
$response = new xajaxResponse();
    
$name = $form_data["name"];
$phone = $form_data["phone"];
$description = $form_data["description"];

$results = "$name<br />$phone<br />$description";
        
$response->Assign("footer","innerHTML", $results);
return $response;
}

Anytime I specify the form's name in the getFormValues function, I get the error in Firebug "child.name.substring is not a function". If I take out the form name, and send one value, it works fine. The name of the form and the values I'm using are correct.