Attachment Loop (Doesn't work)

# Check for attachments
if(isset($results['Related']) || isset($results['Attachments']))
{
    if(isset($results['Related']))
    {
        $attachment_type = $results['Related'];
    }
    elseif(isset($results['Attachments']))
    {
        $attachment_type = $results['Attachments'];
    }

    for($i = 0; ($i < count($results['Attachments']) || $i < count($results['Related'])); $i++)
    {
        # Format file name (change spaces to underscore then remove anything that isn't a letter, number or underscore)
        $filename = preg_replace('/[^0-9,a-z,\.,_]*/i', '', str_replace(' ', '_', $attachment_type[$i]['FileName']));

        /* LOTS MORE CODE HERE */
    }
}