function GetIP() {

        if (!empty($_SERVER['HTTP_CLIENT_IP'])) {

        //如果变量是非空或非零的值，则 empty()返回 FALSE。

            $IP = explode(',',$_SERVER['HTTP_CLIENT_IP']);

        }

        elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {

            $IP = explode(',',$_SERVER['HTTP_X_FORWARDED_FOR']);

        }

        elseif (!empty($_SERVER['REMOTE_ADDR'])) {

            $IP = explode(',',$_SERVER['REMOTE_ADDR']);

        }

        else {

            $IP[0] = 'None';

        }

        return $IP[0];

    }