Codeigniter Ajax Login issue
$(document).keypress(function (e) {
    if (e.which == 13) {
        var login = $("#login").val();
        var pass = $("#pass").val();

        $('#login-block').removeBlockMessages().blockMessage('Please wait, cheking login...', {
            type: 'loading'
        });
        $.post("<?php echo base_url(); ?>index.php/login/validate_credentials/", {
            username: login,
            password: pass
        }, function (data) {
            if (data.error) {
                $('#login-block').removeBlockMessages().blockMessage(data.message, {
                    type: 'error'
                });
            } else {
                document.location.href = data.redirect;
            }
        }, "json");
    }
});

function validate() {

    // CHECK LOGIN DETAILS
    $this->db-> select('first_name,last_name,usertype,id,products,mac');
    $this->db-> where('username', $this->input->post('username'));
    $this->db-> where('password', md5($this->input->post('password')));
    $query = $this->db->get('membership');

    if ($query->num_rows() > 0) {
        $data = array('usertype' => $row->usertype, 'userid' => $row->id, 'first_name' => $row->first_name, 'last_name' => $row->last_name, 'products' => $row->products, 'mac' = > $row->mac);
        return $data;
    }
}

if(data.error){
    $('#login-block').html('<p>'+data.message+'</p>);
} else {
    document.location.href = data.redirect;
}

if($query->num_rows()==1)
{
$data2 = array(
    'error' => false,
    'redirect' => base_url().'index.php/site/home/'
    );

$.getJSON('<?php echo base_url(); ?>index.php/login/validate_credentials/',{username: login, password: pass}, function(data) {
if(data.error){
$('#login-block').removeBlockMessages().blockMessage(data.message, {type: 'error'});
} else {
document.location.href = data.redirect;
}
});