I can't pass post data in my custom module.

filenames:

mymodule.info mymodule.mod

.info

name = My Module
description = My custom module.
package = DEV 
version = 1.0 
core = 7.x

.module

<?php

function mymodule_menu() {
   $items = array();

  $items['getcountries'] = array(
    'title' => 'Get Countries', 
    'page callback' => 'getcountries', 
    'access arguments' => array('access content'), 
    'type' => MENU_CALLBACK, 
    );

 $items['getstates'] = array(
    'title' => 'Get States', 
    'page callback' => 'getstates', 
    'access arguments' => array('access content'), 
    'type' => MENU_CALLBACK, 
    );  

  return $items;
}

function getcountries() {

$result = db_query("select distinct(country) from region");

$jsonarray = Array();

foreach ($result as $record) {

    $jsonarray[] = array(

        'item' => $record->country,
        'value' => $record->country
      );

}

$json = json_encode($jsonarray);

  echo $json;
}

function getstates() {

echo $_POST["test"];

}

Ajax call

$(document).ready(function(){

    $.ajax({
        url: '/getstates',
        type: 'POST',
        data: '{"test":"1"}',
        success : function () {
           alert('ok');
        },
        error : function (jqXHR, textStatus, errorThrown) {
          alert('error');
        }
   });
});

The first item "getcountries" is working fine however the second one is not. I can browse to http://mysite.com/getstates ok but when I call this function using ajax it is not passing the value of "test" which is "1" to $_POST["test"].

I am new to Drupal so I am positive that I miss something here. I thought I need a new set of eyes.