$('#auth_btn').click(function(){
        data={username:$('#username').val(), password:$('#pass').val()};
        $.post('Chat/check', data, function(response){

        });
    });

public function check(){
        $data['username'] = $this->input->post('username');
        $data['password'] = $this->input->post('password');
        $this->load->model('Chat_model', 'cm');
        $user = $this->cm->checkUser($data);
        if($user = true){
            $this->load->view('chat_view');
        }else{
            $data['false'];
            $this->load->view('login_view', $data);
        }

public function check_user($log) {
        $query=$this->db->get_where('username', $log['username']);
        //$this->db->where('password', $log['password']);
        if($query->num_rows > 0) {
            return TRUE;
        } else {
            return FALSE;
        }
    }