CActiveForm->dropDownList selected="selected"

How to mark option in dropDownList as selected="selected"?

I have table users witch have filed: location (this field holds id of entry from table: locations)

I'm retrieving data for dropDownList in this way:

$criteria = new CDbCriteria;
$criteria->order = 'name ASC';
$locations = Locations::model()->findAll($criteria);
$data['locations'] = CHtml::listData($locations, 'id', 'name');

This is snippet from my View:

<div class="row">
    <?php echo $form->labelEx($model,'location'); ?>
    <?php echo $form->dropDownList($model,'location', $locations, array('prompt'=>'Select location')); ?>
    <?php echo $form->error($model,'location'); ?>
</div>

What I have to put in options array in my view so it will work like this pseudocode:

if ($user->location == $locations->id) {
    markOption(selected="selected");
}

Thanks in advance