Magento - Auto choose product attribute in produtct Page

MagentoAutoSelectFunction

<script type="text/javascript">
        var spConfig = new Product.Config(<?php echo $this->getJsonConfig() ?>);
        
        spConfig.setInitialState = function(dropdown_id){        
            var dropdown = $(dropdown_id);//select dropdown        
            dropdown[0].remove();//remove empty option from dropdown so it is not selectable after initial selection
        
            for( index = 0; index < dropdown.length; index++ ){//change selections in dropdowns
                if(dropdown[index].value != ""){
                    dropdown.selectedIndex = index;
                    var element = dropdown;
                    var event = 'change';
                
                    if(document.createEventObject){//fire events        
                        var evt = document.createEventObject();
                        return element.fireEvent('on'+event,evt)
                    } else {
                        var evt = document.createEvent("HTMLEvents");
                        evt.initEvent(event, true, true );
                        return !element.dispatchEvent(evt);
                    }
                }
            }
        };        
    </script>    

MagentoAutoSelectFunctionCall

<?php foreach($_attributes as $_attribute): ?>
  <script type="text/javascript">
    spConfig.setInitialState("attribute<?php echo $_attribute->getAttributeId() ?>")
  </script>
<?php endforeach; ?>