ajax returning true while FALSE - php

Question

I am using codeigniter, i have written a function to check if a user password exists which it does. This is my model
The model: user
public function get_some_password($username,$password) {
$this->db->where('user_password', $password);
$this->db->where('user_username',$username);
$query=$this->db->get('some_users_table');
if($query->num_rows()==1){
return true;
}else{
return false;
}
the controller
public function check_password() {
$username=$this->uri->segment(3);
$temp_pass= $this->input->post('current_password');
$password=md5($temp_pass);
$this->user->get_some_password($username,$password);
}
The ajax on the view
//done on page load
var success1 = $(".success"); //a div on the view that appears if success
var error1 = $(".error"); //a div on the view that appears if error
success1.hide();
error1.hide();
$('#change_password').click(function() {
var username = $('#username').val();
dataString2 = $('#changpassword').serialize();
$.ajax({
type: "POST",
url: '<?php echo base_url(); ?>controller_name/check_password/' + username,
data: dataString2,
success: function() {
$('.success').html('password successfully updated!'),
success1.slideDown('slow');
},
error: function() {
$('.error').html('Wrong current password!'),
error1.slideDown('slow');
}
});
The problem: Ajax loads the success div even when the username or password returned is false, where am i missing something

Answer 1

This is a correct behavior as jquery error is executed when response code is not 200:
1) You can parse returned value in success method.
e.g.
success: function(data) {
if (data == 'true') {
// Success
} else {
// Error
}
}
2) You can return error code from server 404, 500, 503 ... To trigger execution of error function.
e.g.
header("Status: 404 Not Found");
note: Header should executed before any output is done.
Try in your controller:
public function check_password() {
$username=$this->uri->segment(3);
$temp_pass= $this->input->post('current_password');
$password=md5($temp_pass);
if(!$this->user->get_some_password($username,$password)) {
$this->output->set_status_header('500');
return;
}
...
}