gimana ya cara jumlahin smua field dibawah ini di _Form 
kaya pake ajax atau javascript onChange
<div class="form">
<?php $form=$this->beginWidget('CActiveForm', array(
'id'=>'reim-form',
'enableAjaxValidation'=>false,
)); ?>
<p class="note">Fields with <span class="required">*</span> are required.</p>
<?php echo $form->errorSummary($model); ?>
<div class="row">
<?php echo $form->labelEx($model,'id_emp'); ?>
<?php echo $form->textField($model,'id_emp'); ?>
<?php echo $form->error($model,'id_emp'); ?>
</div>
<div class="row">
<?php echo $form->labelEx($model,'breakfast'); ?>
<?php echo $form->textField($model,'breakfast',array('size'=>20,'maxlength'=>20)); ?>
<?php echo $form->error($model,'breakfast'); ?>
</div>
<div class="row">
<?php echo $form->labelEx($model,'lunch'); ?>
<?php echo $form->textField($model,'lunch',array('size'=>20,'maxlength'=>20)); ?>
<?php echo $form->error($model,'lunch'); ?>
</div>
<div class="row">
<?php echo $form->labelEx($model,'dinner'); ?>
<?php echo $form->textField($model,'dinner',array('size'=>20,'maxlength'=>20)); ?>
<?php echo $form->error($model,'dinner'); ?>
</div>
<div class="row">
<?php echo $form->labelEx($model,'otherfood'); ?>
<?php echo $form->textField($model,'otherfood',array('size'=>20,'maxlength'=>20)); ?>
<?php echo $form->error($model,'otherfood'); ?>
</div>
<div class="row">
<?php echo $form->labelEx($model,'hotel'); ?>
<?php echo $form->textField($model,'hotel',array('size'=>20,'maxlength'=>20)); ?>
<?php echo $form->error($model,'hotel'); ?>
//INI TOTAL SMUA FIELD OTOMATIS MASUK KSINI KALO UDAH INPUT FIELD-FIELD DIATAS
<div class="row">
<?php echo $form->labelEx($model,'total'); ?>
<?php echo $form->textField($model,'total',array('size'=>20,'maxlength'=>20)); ?>
<?php echo $form->error($model,'total'); ?>
</div>
<div class="row buttons">
<?php echo CHtml::submitButton($model->isNewRecord ? 'Create' : 'Save'); ?>
</div>
<?php $this->endWidget(); ?>
</div><!-- form -->