add plug-in, can't submit

[Easy5s.net]

Hello,
I have a plug-in:

if ($vbulletin->options['enable'] AND (THIS_SCRIPT=='newthread'))
{
	if (in_array($forumid, explode(",", $vbulletin->options[enable_forumid'])))
	{
		$getinfos = $vbulletin->db->query_read("
			SELECT postuserid, threadid, postdate 
			FROM " . TABLE_PREFIX . "testting
			WHERE postuserid = " . $vbulletin->userinfo['userid'] . "
			GROUP BY threadid
			ORDER BY threadid ASC
		");	
		$count = $vbulletin->db->num_rows($getinfos);
		if ($count = 0)
		{
			$mytest = '<option value="0" selected="selected">0</option>';
			while ($getinfo = $vbulletin->db->fetch_array($get_infos))
			{
				$mytest = '<option value="' . $getinfo[threadid] . '">'. $getinfo[threadid] . '</option>';
			}
		}

	}
}

I put it in hook newthread_start, but when I click submit it does not work (can not new thread). Pls help me.
Thank

This is video: http://www.youtube.com/watch?v=sNtKvZ90Ews