php - I do not get a response after a post JavaScript CodeIgniter -

i have dropdown courses names(like 'php', 'c', 'c#' ... ). have onchange event put on can check if option drop-down valid(is found in database) - it may seem stupid, myself puting values in dropdown database, doing protecting against sql injection.

the problem not receive response verifycourse.php ... there wrong.

function.js

function complete() {     $.post("verifycourse/domain", {         domain: $('#domain').val().tolowercase()     }).done(function (returnvalue) {         alert('after post'); //it not alert         var result = jquery.parsejson(returnvalue);         if (result['returnvalue'] == 'ok') {             alert('good domain');         }         else if (result['returnvalue'] == 'wrong') {             alert('wrong domain');         }     }); } 

verifycourse.php

function index($param = 1)   {     parent::__construct();     $this->load->model('user','',true);     $this->load->library( 'mysmarty' );      $smarty = new mysmarty ;      if (isset($param) && $param == 'domain') {         $this->isvalidcourse($this->input->post('domain'));     }   }      function isvalidcourse($coursename)     {         $query = $this->db->get('admins');          $arr = $this->user->getdomains($coursename);         if(in_array($coursename, $arr))             return json_encode(array('returnvalue' => 'ok'));         return json_encode(array('returnvalue' => 'wrong'));     } 

user.php

function getdomains()     {         $query = $this->db->get('admins');          $arr = array();         foreach ($query->result() $row) {             if ($row->subject && !(in_array($row->subject, $arr)))                 $arr[] = $row->subject;         }          return $arr;     } 

home_view.tpl

<div class="modal-body">                 <form class="contact" name="contact">                     <font color="red"><div id="errors"></div></font>                     <input type="text" class="input-block-level" id="coursename" placeholder="course name" name="coursename"/>                     <br/>                     <select class="input-block-level" id="domain" placeholder="domain name" name="domain" onchange="complete();">                       {foreach from=$myarray item=foo}                           <option value="foo">{$foo}</option>                       {/foreach}                     </select>                        </form>             </div> 

change $.post $.ajax in order catch other errors, this:

$.ajax({     type: "post",     url: "verifycourse/domain",     data: {domain: $('#domain').val().tolowercase()},     success: function(msg){         alert(  msg );     },     error: function(xmlhttprequest, textstatus, error) {         alert("some error");         console.log(xmlhttprequest);         console.log(textstatus);         console.log(error);    } });