gistfile1.phtml

<div class="control-group ">
    <label for="Duration_used_by_customer" class="control-label">Used By Customer</label>
    <div class="controls">
        <?php $radio = $this->beginWidget('zii.widgets.jui.CJuiButton', array(
            'name'       => 'btnradio',
            'buttonType' => 'buttonset'
        )); ?>
        <input type="radio" id="radio1" name="Duration[used_by_customer]" value="Yes" <?php if ($model->used_by_customer == 'Yes') echo 'checked="checked"' ?> /><label for="radio1">Yes</label>
        <input type="radio" id="radio2" name="Duration[used_by_customer]" value="No" <?php if ($model->isNewRecord || $model->used_by_customer == 'No') echo 'checked="checked"' ?> /><label for="radio2">No</label>
        <?php $this->endWidget();?>
        <span style="display: none" id="Duration_used_by_customer_em_" class="help-inline error"></span>
    </div>
</div>