Magento : Configurable Product Collection with simple product attribute value

<div class="home-product">
    <ul class="feat-pro">
        <?php
        $categoryid = 4;
        $category = new Mage_Catalog_Model_Category();
        $category->load($categoryid);
        $collection = $category->getProductCollection();
        $collection->addAttributeToSelect('*');
        $count=4;
        $i=0;
        $cnt=count($collection);
        foreach ($collection as $_product) {  $i++;?>
        <li><div class="product-image">
                <a href="<?php echo $_product->getProductUrl() ?>"><img src="<?php echo $this->helper('catalog/image')-> init($_product, 'small_image')->resize(291,432); ?>"  alt="" /></a> <a href="<?php echo $_product->getProductUrl(); ?>"></a>
            </div>
            <div class="product-size">
                <div class="attribute-name">
                <h3><?php echo $this->__('Size') ?></h3>
                </div>
                <?php 
              
                if($_product->isConfigurable()) {
                    $_helper2 = Mage::getModel('catalog/product_type_configurable')->setProduct($_product);
                    $_subproducts = $_helper2->getUsedProductCollection()->addAttributeToSelect('size')->addFilterByRequiredOptions(); 
                    $_size = array();
                    $_size_id = array();
                    
                    
                    foreach ($_subproducts as $_subproduct) {
                   
                    
                        $label = $_subproduct->getAttributeText('size');
                        $_size[] = $label;
                        
                            if (!isset($_size_id[$label])) {
                                $_size_id[$label] = $_subproduct->getData('size');
                            }
                    }
                    
                    
                    $_size_swatch = array_unique($_size);
                    
                    echo '<ul class="size-swatch clearer">';
                    
                        foreach($_size_swatch as $_inner_option_id){
                            echo '<li class="size-li-' . $_inner_option_id . '"><div class="size-' . $_inner_option_id . '">' . $_inner_option_id . '</div></li>';
                        }
                    
                    echo '</ul>';
                }
                
                ?>  
            </div>
            <h2><?php echo $_product->getName(); ?></h2>
            <div class="product-price">
                <?php
                    $org_prc=($_product->getPrice());
                    $sp_prc=($_product->getSpecialPrice());
                        if($sp_prc==0){ ?>
                            <div class="org-price">  
                                <?php    echo $orgPrice = Mage::helper('core')->currency($org_prc, true, false); ?>
                            </div>
                            <?php }
                            else { ?>
                            <div class="sp-price">
                                <div class="sp-spprice">
                                    <?php  echo  $spcPrice = Mage::helper('core')->currency($sp_prc, true, false); ?>
                                </div>
                                <div class="sp-org-price">
                                    <?php echo $orgPrice = Mage::helper('core')->currency($org_prc, true, false); ?>
                                </div>
                            </div>
                           
                            <?php  } ?>
            </div>
             <div class="product-details">
                <span class="icon"></span>
                <a title="<?php echo $this->__('BUY NOW') ?>" class="button" href="<?php echo $_product->getProductUrl() ?>"><?php echo $this->__('BUY NOW') ?></a>
             </div>
                        <?php if($i==$cnt)break; ?>
                        <?php if($i%$count==0) { ?></li></ul> <ul class="feat-pro"> <?php } ?>
        </li>
        <?php } ?>
    </ul> 
</div>