Where To Write Jquery,ajax Code In Custom Autocomplete Text Field

Hi all,

I"m trying to write custom auto complete for text field. can anyone pls tell me where to write this jquery, ajax code for this textfield in yii..

<div id="output" class="row">
	<?php echo $form->labelEx($model,'id'); ?>
  <?php echo $form->hiddenField($model,'id'); ?>
  <?php echo $form->textField($model,'id');
  '$("#search").change(function(){
  
  $.ajax({url:BASE_URL + '/controller/lookup/',
  		type:"POST",
  		data:this.value,
  		success:function(data){
  		$("div").innerHTML()
  }
  });
  
  });'?>

Many Thanks