problem with adding a EchMultiSelect with dropDownAttribute

[drusixtynine (Yii)]

I am quite new to yii and I came to this company where an application was developped with yii 1.1 and I have to maintain it now

I have a bit of difficulties to understand what came with the framework and what came from the development team

I am asked to modify a search form that seems to use EchMultiSelect extension

I went through some code and I want to add a multi select list box to this form, but I am having some problems

I tried to add this code

       <span style="width: 50%;" class="cell">


	<?php echo $form->label($model, 'Régie'); ?>


            <?php $this->widget('ext.widgets.EchMultiSelect.EchMultiSelect', array( 


                'model' => $model,


                'dropDownAttribute' => 'regie',     


                'data' => GxHtml::listDataEx(regie::model()->findall('statut="Actif"')),


                'dropDownHtmlOptions'=> array(


                   'style'=>'width:225px;',


                ),


                'options' => array( 


                    'checkAllText' => Yii::t('application','Tous'),


                    'uncheckAllText' => Yii::t('application','Aucun'),


                    'selectedText' =>Yii::t('application','# choix'),


                    'selectedList'=>25,


                    'noneSelectedText'=>'',


                    'multiple'=>true,


                    'filter'=>true,     


                ),


                'filterOptions'=> array(


                    'label' => Yii::t('application','Filtre:'),


                    'width'=>125,


                    'placeholder'=>Yii::t('application','Rechercher'),


                ),


            )); ?>


        </span>  

but it is giving the following error (translated from french) when I am showing the form

The property « Pige.regie » is not defined

which pige is a table on my database and this form is the file _search of models/pige

the problem is when I use name instead of dropDownAttribute and model, it shows the form correctly, and I do want to understand why it works in a case and not the other and if something is missing in my model

       <span style="width: 50%;" class="cell">


	<?php echo $form->label($model, 'Régie'); ?>


            <?php $this->widget('ext.widgets.EchMultiSelect.EchMultiSelect', array(  


                'name' => 'regie',     


                'data' => GxHtml::listDataEx(regie::model()->findall('statut="Actif"')),


                'dropDownHtmlOptions'=> array(


                   'style'=>'width:225px;',


                ),


                'options' => array( 


                    'checkAllText' => Yii::t('application','Tous'),


                    'uncheckAllText' => Yii::t('application','Aucun'),


                    'selectedText' =>Yii::t('application','# choix'),


                    'selectedList'=>25,


                    'noneSelectedText'=>'',


                    'multiple'=>true,


                    'filter'=>true,     


                ),


                'filterOptions'=> array(


                    'label' => Yii::t('application','Filtre:'),


                    'width'=>125,


                    'placeholder'=>Yii::t('application','Rechercher'),


                ),


            )); ?>


        </span>