请问php通过curl如何模拟登陆阿里妈妈呢？

登陆的时候提示：超人，您提交的页面已过期，请重新输入提交
以下是我写的模拟登陆代码，技术比较菜，勿笑，请问有什么问题呢？
public function curl(){
$url='https://www.alimama.com/member/minilogin_act.htm';
$url2='http://www.alimama.com/member/minilogin.htm';
$data['_tb_token_']=$this->g($url2);
$data['style']='';
$data['redirect']='';
$data['proxy']='http://www.alimama.com/proxy.htm';
$data['logname']='aaaaaa;
$data['originalLogpasswd']='bbbbb';
$data['logpasswd']='567aassssssssssssssssssssssss0f4';
$fields=array_map('urlencode', $data);
$cookie_file = "d:\cookie.txt";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows NT 6.1; rv:25.0) Gecko/20100101 Firefox/25.0');
curl_setopt($ch, CURLOPT_RETURNTRANSFER,0);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION,1);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $fields);
curl_setopt($ch, CURLOPT_COOKIEJAR, $cookie_file);
curl_setopt($ch, CURLOPT_COOKIEFILE, $cookie_file);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_exec($ch);
curl_close($ch);
}