If any field of the form is unchanged then set flag to 1, and if any field of the form is changed then set flag to 0. Below is view:
<div class="row">
<?php echo $form->labelEx($model,'name'); ?>
<?php echo $form->textField($model,'name'); ?>
<?php echo $form->error($model,'name'); ?>
</div>
<div class="row">
<?php echo $form->labelEx($model,'email'); ?>
<?php echo $form->textField($model,'email'); ?>
<?php echo $form->error($model,'email'); ?>
</div>