cakephp Ajax: city select box not populating when state is selected -

i'm trying populate city select box based on selected state (which select box) using ajax. when select state, city select box not being populated.

there 5 models below: student, merryparent, merryclass, state, city. of them related 1 another.

can please tell me on doing wrong? thank you.

the following models: student.php

 <?php  class student extends appmodel{ var $name='student'; var $belongsto=array('merryparent','state','city','merryclass');            }       ?> 

merry_parent.php

     <?php      class merryparent extends appmodel{ var $name='merryparent'; $hasmany=array(         'student'=>array(         'classname'=>'student',         'foreignkey'=>'merry_parent_id'                 )             ); $belongsto=array('state','city','merryclass');                       ?> 

merry_class.php

         <?php             class merryclass extends appmodel{          var $name='merryclass';          var $hasmany=array     ('student'=>array(             'classname'=>'student',             'foreignkey'=>'class_id'             ),      'merryparent'     );         var $belongsto=array('state','city');         //var $displayfield='class_name';            }           ?> 

city.php

      <?php         class city extends appmodel{     var $name='city';     var $belongsto='state';     var $hasmany=array('merryparent','merryclass',             'student'=>array(                 'classname'=>'student',                 'foreignkey'=>'city_id'                 )             );                  }         ?> 

state.php

               <?php                       class state extends appmodel{                          var $name='state';                          var $hasmany=array(             'merryparent',             'merryclass',             'city'=>array(             'classname'=>'city',             'foreignkey'=>'state_id'             //'dependent'=>true             ),             'student'=>array(             'classname'=>'student',             'foreignkey'=>'state_id'             )         );                }              ?> 

the controllers students_controller.php

<?php class studentscontroller extends appcontroller{  var $name='students';  var $helpers = array('html','form','ajax','javascript');  var $components=array('requesthandler');  function getcities(){      $options=$this->student->city->find('list',                                     array                                     ('conditions'=>array(                                                     'city.state_id'=>$this->data['student']['state_id']                                                     ),                                      'group'=>array('city.name')                                     )                                 );//closing parentheses find('list'...       $this->render('/students/ajax_dropdown'); }   function add(){       if (!empty($this->data)){         /*var_dump($this->data);         die(debug($this->student->validationerrors)); */         $student=$this->student->saveall($this->data,array('validate'=>'first'));         if (!empty($student))            {             $this->session->setflash('your child\'s admission has been received. send email shortly.');                     $this->redirect(array('controller'=>'pages', 'action'=>'home'));              }       } //for if (!empty....       $states=$this->student->state->find('list');      $cities=array();       $this->set(compact('states','cities'));  }//end function 

} ?>

merry_parents_controller.php

<?php  class merryparentscontroller extends appcontroller{  var $name='merryparents';    }  ?> 

add.ctp

  <?php  echo $javascript->link('prototype',false);   echo $form->create('student'); echo '<fieldset>'; echo '<legend>student information</legend>'; echo $form->input('student.name');  $options = array('male'=>'male','female'=>'female'); $attributes = array('value'=>'male'); echo $form->radio('student.gender',$options,$attributes);  echo $form->input('student.dob', array('label'=>'date of birth',                 'dateformat'=>'dmy',                  'empty'=>true,                 'timeformat' => '',              'minyear' => (                      date('y') - 5              ),              'maxyear' => (                      date('y') - 2              )              )); echo $form->input('student.class_id',          array(         'label'=>'enquiry class for',         'empty'=>'choose one', 'options'=>array('1'=>'playgroup','2'=>'nursery','3'=>'lkg', '4'=>'ukg')         )         );  echo '</fieldset>';  echo '<fieldset>'; echo '<legend>parent information</legend>'; //echo $form->input('student.parent_id', array('type'=>'hidden')); echo $form->input('merryparent.initial',  array('empty'=>true, 'options'=>array('dr'=>'dr',                  'mr'=>'mr',                  'mrs'=>'mrs',                  'ms'=>'ms') ) ); echo $form->input('merryparent.name', array('label'=>'parent/guardian name')); echo $form->input('merryparent.email'); echo $form->input('merryparent.landline'); echo $form->input('merryparent.mobile'); echo $form->input('merryparent.address');       echo $form->input('student.state_id');  echo $form->input('student.city_id');       echo $form->input('merryparent.postal_code');        $options = array('url' => 'getcities', 'update' => 'studentcityid');   echo $ajax->observefield('studentstateid', $options); //observes drop down      changes in state id , makes xmlhttprequest when contents have changed.       echo '</fieldset>';  echo $form->end('submit');     ?> 

ajax_dropdown.ctp

     <?php foreach($options $k=>$v) : ?>       <option value="<?php echo $k; ?>"><?php echo $v; ?></option>      <?php endforeach; ?> 

you don't need put 0 in model name , field, since saving 1 student in form. try using student.name instead of student.0.name , on fields. try test $validate => false if saves then.