Ajax if not working. How to it work?

The if in this block making the website to hang. If I remove the "if" it works perfectly. But I need to add the variable check for lock. How can I do it?

$.ajax({
    url: '<?php echo $this->createUrl(' //customer/financial/paymentplan',array('name'=>'Contract[paymentplanservicefee]','countryid'=>'')); ?>' + $('#Customer_countryid').val(),
    success: function (data) {
        if ($locked) $('#paymentplanselect').html(data);
    },
});

In this file I also have this thing for the view.

<td>
                        <div id='paymentplanselect'><?php
                            $listdata = Financial::getPaymentPlans($model->countryid);
                            echo $form->dropDownList($contract, 'paymentplanservicefee', $listdata, array('empty'=>' - select payment plan - ', 'disabled'=>$locked)); 
                        ?></div>
                        <?php echo $form->error($contract,'paymentplanservicefee'); ?>
                    </td>