title: yii set selected dropdownlist from other dropdownlist
body: <p>i have 4 dropdownlist, 1 dropdownlist as master to control 3 dropdownlist other, this my sample code for master dropdownlist.</p>
  
  <pre><code>&lt;div class="row"&gt;
          &lt;?php echo $form-&gt;labelEx($truck,'Truck'); ?&gt;
          &lt;?php echo CHtml::dropDownList('idt',$truck-&gt;idt,CHtml::listData(Truck::model()-&gt;findAll(),'idt','number'),
          array(
              'value'=&gt;'1',
              'ajax' =&gt; array(
                  'type'=&gt;'POST', 
                  'url'=&gt;CController::createUrl('FindTruck'),             
                  'data'=&gt;array('idt'=&gt;'js:this.value'),
                  'dataType'=&gt;'html',
  
              ))); ?&gt;
      &lt;/div&gt;
  
      &lt;div class="row"&gt;
  
          &lt;?php echo $form-&gt;labelEx($employee,'Driver'); ?&gt;
          &lt;?php echo CHtml::dropDownList('driver','$variable',CHtml::listData(Employe::model()-&gt;findAll(),'ide','name')); ?&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p>This My js setDriver</p>
  
  <pre><code>function setDriver(name,value){
      document.getElementById(name).value = value
  }
  </code></pre>
  
  <p>and this my controller</p>
  
  <pre><code>public function actionFindTruck() {
     echo "&lt;script&gt;setDriver('driver',3);&lt;/script&gt;"; // test satatic data
  }
  </code></pre>
  
  <p>the question what code must i write on controller (ActionFindTruck) to change value of $variable above, so if i change Truck, the Driver will be change selected.<br>
  Thanks for help.</p>